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SAQIB IMRAN 0341-7549889 1
Assala mu alykum My Name is saqib imran and I am the
student of b.tech (civil) in sarhad univeristy of
science and technology peshawer.
I have written this notes by different websites and
some by self and prepare it for the student and also
for engineer who work on field to get some knowledge
from it.
I hope you all students may like it.
Remember me in your pray, allah bless me and all of
you friends.
If u have any confusion in this notes contact me on my
gmail id: Saqibimran43@gmail.com
or text me on 0341-7549889.
Saqib imran.
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SAQIB IMRAN 0341-7549889 2
How to Calculate the Square Meters of a Room
To calculate a rectangular room's area in square meters, multiply its length in meters by its
width in meters. If the room is an odd shape, break the shape down into individual rectangles,
calculate the area in square meters for each rectangle, and then add the areas of all the
rectangles for the room's total area in square meters.
Measure Length and Width
To calculate the area of a room, you need to know its length and width. Since you want the
result in square meters, both measurements should be taken in meters. Most measuring tapes
have metric measurements along one side, so just make sure you read the right side of the tape
and always write down the measurements to cut down on mistakes and to keep from having to
remeasure if you forget.
Converting Meters to Feet
If you've already measured the room in feet, you don't have to remeasure. Instead, grab a
calculator and make the conversion to meters by dividing the number of feet in each
measurement by 3.2808. If your room measures 13 feet long on one side, after the conversion,
you have 13 ÷ 3.2808 = 3.96 meters.
Calculating the Area of a Room
Now that you know the room's length and width in meters, you calculate its area using the
formula length × width = area. If the room is 4 meters long and 3 meters wide, its area is 4
meters × 3 meters = 12 square meters. If the room is 6 meters long and 5 meters wide, its area
is 6 meters × 5 meters = 30 square meters. When you multiply one measurement in meters by
another measurement in meters, the result should always be labeled as square meters to avoid
confusion. You can also write square meters as meters2, which is read as meters squared.
Measuring Odd-Shaped Rooms
The formula works if your room is a square or rectangle shape, but sometimes rooms are L-
shaped, or maybe you want to measure the free floor space around the furniture that's already
in the room. In that case, the easiest method is to break the room's shape into individual
rectangles. Calculate the area of each rectangle in square meters and then add the areas to get
the total area of the room in square meters. If you have an L-shaped room that you broke down
into two rectangles – one measuring 2 meters by 5 meters and the other measuring 5 meters
by 4 meters – the area of the first rectangle is 2 meters × 5 meters = 10 square meters, and the
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area of the second rectangle is 5 meters × 4 meters = 20 square meters. Add those together to
get the total area of the room: 10 square meters + 20 square meters = 30 square meters.
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Calculating an Area in Square Meters
Measure the length of the area you're measuring. Square meters are a unit for measuring area,
or the size of a two-dimensional object such as a floor or a field. Use your measuring tool to
measure one side of the object, from one corner to the other. Write down the result.
 If the object is longer than 1 meter, remember to include both the meter and
centimeter parts of the measurement. For instance, "2 meters 35 centimeters."
 If you want to measure an object that isn't rectangular or square, read the Complex
Shapes section instead.
If you can't measure the entire length at once, do it in stages. Lay out the measuring tool, then
put down a rock or other small object exactly at an easy to remember mark (like 1 meter or 25
centimeters). Pick up the tool and lay it down again, starting at the small object. Repeat until
the entire length is covered, and add all your measurements together.
Measure the width. Use the same tool to measure the width of the same area or object. The
side you measure in this step should be angled close to 90º away from the length of the object
you measured earlier, like two sides of a square next to each other. Write this number down as
well.
 Unless the object you're measuring is much smaller than 1 meter, you can round to the
nearest centimeter when making your measurements. For instance, if the width is
slightly past the 1 meter 8 centimeter mark, just use '"1m 8cm" as your measurement,
without using decimals or millimeter measurements.
Convert from centimeters to meters. Usually, the measurements won't divide evenly
into meters. Instead, you'll have a measurement in both meters and centimeters, for example
"2 meters 35 centimeters." Because 1 centimeter = 0.01 meters, you can convert a centimeter
measurement into meters by moving the decimal point two digits to the left. Here are a couple
examples:
 35cm = 0.35m, so 2m 35cm = 2m + 0.35m = 2.35m
 8cm = 0.08m, so 1m 8cm = 1.08m
Multiply the length and width together. Once both measurements are converted into
meters, multiply them together to get the measurement of the area in square meters. Use a
calculator if necessary. For example:
 2.35m x 1.08m = 2.538 square meters (m2).
Round to a more convenient measurement. If you get a long decimal as an answer, for instance
2.538 square meters, you'll probably want to round it to a number with fewer digits, for
instance 2.54 square meters. In fact, since you probably didn't measure correctly down to the
tiniest fraction of a meter, the last digits probably aren't accurate anyway. In most cases, you
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can round to the nearest centimeter (0.01m). For a more accurate measurement, learn how to
round to the significant digits.
Whenever you multiply two numbers with the same units (for instance, meters), the answer is
always in the form of that unit squared (m2, or square meters).
Converting from Other Units
Multiply square feet by 0.093. Measure the length and width in feet and multiply them
together to get a result in square feet. Since 1 square foot = 0.093 square meters, multiply your
result by 0.093 to get the answer in square meters instead. Square meters are bigger than
square feet, so it will take fewer of them to cover the same area.
For greater precision, multiply by 0.092903 instead.
Multiply square yards by 0.84. If you have the measurement in square yards, multiply by 0.84
to get the measurement in square meters.
For greater precision, multiply by 0.83613 instead.
Multiply acres by 4050. One acre contains about 4050 square meters. If you want to be more
precise, multiply by 4046.9 instead.
Convert square miles to square kilometers instead. One square mile is much, much larger than
a square meter, so typically it is converted into square kilometers instead. Multiply the square
miles by 2.6 to find the area in square kilometers instead. (Or multiply by 2.59 instead to be
more precise.)
If you really want to convert to square meters, 1 square kilometer = 1,000,000 square meters.
Convert square meters to units of area, not length. Square meters are a unit that
measures area, or two-dimensional surfaces. It doesn't make any sense to compare them with
units that measure length, or distance in one direction. You can convert between "square
meters" and "square feet," but not between "square meters" and "feet."
Don't use the calculations in this section to convert between units of length. That
requires different numbers.
Calculating Square Meters for a Complex Shape
Break the shape up into pieces. If you are solving a math problem, draw or cut lines in the
shape to divide it into simpler shapes, such as rectangles and triangles. If you are measuring a
room or other physical object, sketch a diagram of the area first, then do the same thing. Take
measurements of each section and write them on the diagram. Follow the instructions below to
find the area of each section, then add the results together.
Measure rectangle shaped pieces as you would normally. To find the area in square meters for
rectangular sections, see the instructions for calculating an area in square meters.
If you are measuring in a different unit, look at the section on other units.
Measure right triangles similarly, then divide by two. A right triangle, which has a 90º angle just
like the corners of a square, has an area easy to calculate. Measure the two sides next to that
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90º corner (the length and width), multiply them together, then divide by two to get the
answer in square meters.
This works because a right triangle is exactly the size of a rectangle cut in half. Basically, you
found the area of a rectangle as usual, then divided by two to get the area of the triangle.
Turn other triangles into right triangles, then measure them. Draw a line from any corner of a
triangle to the opposite side, so that the line hits the opposite side at a 90º angle (picture the
corner of a square). You've just divided the triangle into two pieces, each one a right triangle!
See above for instructions on how to find the area of a right triangle; measure each of the two
sub-triangles separately, and add them together.
Calculate the area of a circle. The area of a circle is πr2, where r is the radius, or distance from
the center of the circle to the rim, or perimeter. Measure this distance, multiply it by itself, then
multiply the result by π on a calculator. If you don't have a calculator with a π function, use 3.14
instead (or 3.1416 if high precision is required).
 If you're not sure where the center is, have a friend hold a tape measure and walk
around the edge of the circle. Hold the other end of the tape measure and adjust your
position until the measurement stays the same while your friend walks around the
entire edge.
 More complicated curved boundaries require more advanced math to calculate. If you
are measuring a room for practical purposes, it might be easier to estimate the area by
pretending the curved surfaces are a series of straight lines.
How many square meters is 30 cm by 15 meters?
30 cm x 15 meters = 0.3 m x 15 m = 4.5 square meters.
What is the difference between a square meter and metre squared?
They're two ways of saying the same thing. The latter is the British way of saying it.
How do I convert square meters to feet?
If you mean square feet, there are 10.76 square feet in one square meter.
How do I convert 20 meters in to square meters?
If the length and width of the space are both 20 meters, 20 x 20 = 400 square meters.
How do I calculate how many tiles I need in a square meter?
Find the area of the tile by multiplying its length by its width. Then divide that area into one
square meter. That tells you how many tiles will fit into a square meter. For example, if a tile is
a square 5 cm on a side, its area is 25 cm². A square meter contains 10,000 cm², so you'd divide
25 into 10,000 to get 400, the number of tiles you'd need to cover a square meter.
How do I calculate cost per square meter?
Divide total cost by the number of square meters.
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How many feet is in a lot that is 6 x 10 meters in dimension?
If you're asking about square feet, you would multiply the two lengths and then multiply by
10.76 (the number of square feet in a square meter).
How many square meters equal a square foot?
There are 10.76 square feet in one square meter. That means there is 0.093 square meter in
one square foot.
How do I calculate the area of a triangle?
Multiply the length of a base of the triangle by the length of the corresponding altitude and
divide the product by two.
How many times does 370mm by 3m fit into 45 square meters?
Convert mm to m, multiply the two lengths together, then divide that into 45.
Methods of Measurements and Units of Civil
Construction Works
The methods and units of measurements for civil construction works are
mainly categorised for their nature, shape and size and for making payments
to the contractor. The principle of units of measurements normally consists
the following:
a) Single units work like doors, windows, trusses etc., are expressed in
numbers.
b) Works consists linear measurements involve length like cornice, fencing,
hand rail, bands of specified width etc., are expressed in running metres
(RM)
c) Works consists areal surface measurements involve area like plastering,
white washing, partitions of specified thickness etc., and are expressed in
square meters (m2)
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d) Works consists cubical contents which involve volume like earth work,
cement concrete, Masonry etc are expressed in Cubic metres.
Table below shows units of measurement of various items of civil
engineering works based on IS 1200.
Sl.
No.
Particulars of item Units of
measurement
Units of
payment
1 Earthwork
1. Earthwork in excavation CUM Per CUM
2. Earthwork in filling in foundation trenches CUM Per CUM
3. Earth work in filling in plinth CUM Per CUM
2 Concrete
1. Lime concrete in foundation CUM Per CUM
2. Cement concrete in lintels CUM Per CUM
3. RCC in slab CUM Per CUM
4. Cement concrete or RCC in chujja, sunshade CUM Per CUM
5. Lean concrete in roof terracing (thickness specified) SQM Per SQM
6. Cement concrete bed CUM Per CUM
7. Reinforced concrete sunshade (specified width and
height)
CUM Per CUM
3 Damp proof course (DPC) – thickness mentioned SQM Per SQM
4 Brick work
1. Brickwork in foundation CUM Per CUM
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2. Brickwork in plinth CUM Per CUM
3. Brickwork in super structure CUM Per CUM
4. Thin partition walls SQM Per SQM
5. Brickwork in arches CUM Per SQM
6. Reinforced brickwork CUM Per CUM
5 Stone work
1. Stone masonry CUM Per CUM
6 Wood work
1. Doors and windows frames or chaukhats, rafters, beams CUM Per CUM
2. Shutters of doors and windows (thickness specified) SQM Per SQM
3. Doors and windows fittings (like hinges, tower bolts,
sliding bolts, handles)
Each Per Each
7 Steel work
1. Steel reinforcement bars etc. in RCC and reinforced brick
work
Quintal Per Quintal
2. Bending, binding of steel reinforcement Quintal Per quintal
3. Rivets, bolts and nuts, anchor bolts, lewis bolts, holding
down bolts
Quintal Per quintal
4. Iron hold fasts – –
5. Iron railing (height and types specified) – –
6. Iron grills SQM Per SQM
8 Roofing
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1. RCC and RB slab roof (excluding steel) CUM Per CUM
2. Lean concrete roof over and inclusive of tiles or brick or
stone slab etc. (thickness specified)
SQM Per SQM
3. Centering and shuttering formwork SQM Per SQM
4. AC sheet roofing SQM Per SQM
9 Plastering, points and finishing
1. Plastering – cement or lime mortar (thickness and
proportion specified)
SQM Per SQM
2. Pointing SQM Per SQM
3. White washing, color washing, cement washing, (number
of coats specified)
SQM Per SQM
4. Distempering (number of coats specified) SQM Per SQM
5. Painting, varnishing (number of coats specified) SQM Per SQM
10 Flooring
1. 25mm cement concrete over 75mm lime concrete floor
(including lean concrete)
SQM Per SQM
2. 25mm or 40mm cement concrete floor SQM Per SQM
3. Doors and window sills (CC or cement mortar plain) SQM Per SQM
11 Rain water pipe / plain pipe RM Per RM
12 Steel wooden truss Each Per each
13 Glass panels (supply) SQM Per SQM
14 Fixing of glass panels or cleaning Each Per Each
Note:
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 SQM = Square meter
 CUM = Cubic meter
 RM = Running meter
Methods for Measurement of civil engineering
works:
The rules for measurement of each item are invariably described in IS –
1200. However some of the general rules are listed below:
1. Measurement shall be made for finished item of work and description of
each item shall include materials, transport, labour, fabrication tools and
plant and all types of overheads for finished the work in required shape, size
and specification.
2. In booking, the order shall be in sequence of length, breadth and height
or thickness.
3. All works shall be measured subject to the following tolerances.
 Linear measurement shall be measured to the nearest 0.01m.
 Areas shall be measured to the nearest 0.01 SQM
 Cubic contents shall be worked out to the nearest 0.01 cum.
4. Same type of work under different conditions and nature shall be
measured separately under separate items.
5. The bill of quantities shall fully describe the materials, proportions,
workmanships and accurately represent the work to be executed.
6. In case of masonry (stone or brick) or structural concrete, the categories
shall be measured separately and the heights shall be described as:
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 From foundation to plinth level
 From plinth to first floor level
 From first floor to second floor level and so on.
Units of Measurement for Payments of Civil
Construction Works
Units of Measurements for payment of construction works in civil
engineering projects are given in table below:
Sl.
No.
Civil Construction Works Units of
measurement
Unit of
payment
1 Earthwork: Excavation, filling, cutting, banking m3
100 m3
2 Surface dressing m2
m2
3 Cutting of trees Number Per
number
4 Stones: quarrying, blasting m3
m3
5 Concrete: PCC, RCC, Precast m3
m3
6 Jail works m2
m2
7 Damp proof course m2
m2
8 Brick work of any description m3
m3
9 Thin partition wall m2
m2
10 String course, drip course, water course
coping etc.
m m
11 Stone work of any description m3
m3
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12 Stone work in wall facing (thickness specified) m2
m2
13 Wood work: truss, rafter, beam etc. m3
m3
14 Door, window shutters m2
m2
15 Door, window fittings Number Per
number
16 Timbering, boarding, sawing of timber,
timbering of trenches, partition, etc.
m2
m2
17 Steel work Quintal Per quintal
18 Expanded metal, fabric reinforcement, cutting
angles, plates, tees
cm2
cm2
19 Threading; welding; solder of sheets cm Per cm
20 Iron gate, grill collapsible gate, rolling shutter m2
m2
21 Iron railing m m
22 Roofing: tiled, corrugated iron, caves board
(thickness specified)
m2
m2
23 Centering, shuttering m2
m2
24 Ridges; valleys; gutters (girth given) m m
25 Expansion and contraction joints m m
26 Ceiling timber, A.C. sheet, board, etc. m2
m2
27 Plastering; pointing; white washing;
distempering; painting; varnishing; polishing;
coal tarring; removing of paints
m2
m2
28 Flooring of any kind m2
m2
29 Pipes, laying of pipes m m
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30 Dismantling of brick masonry m3
m3
31 Grouting m2
m2
32 Grouting of cracks, joints m m
33 Supply of sand; brick ballast; aggregates;
timber
m3
m3
34 Supply of cement Bag Per bag
35 Supply of steel, G.I. sheet, bare electric line Quintal Per quintal
36 Supply of GI sheet m2
m2
37 Supply of sanitary items Number Per
number
38 Supply of paint, varnishes Liter Per liter
39 Supply of explosives, stiff paint Kg Per kg
Measurement of Masonry Brick Works in
Construction including Deductions
Measurement of masonry works in construction is required for calculation of
quantities of materials in masonry and to measure completed work. Masonry
works are those where cement and fine aggregates without any coarse
aggregates are used for construction purpose.
There different types of masonry work:
1. Brick Masonry
2. Concrete block / brick masonry
3. Stone / rubble masonry
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4. Clay tiles, etc.
Measurement of Masonry Works:
Masonry works are such as brick masonry, concrete block, stone or rubble
masonry are generally measured in volume, but are also measured in terms
of area where the thickness of masonry is limited to single brick or single
block. Tiling is measured in area.
While measuring the quantities of masonry work, the wastage of materials
such as bricks, cement or sand is not taken into account. Also, the types and
classes of bricks, blocks or tiles are not considering while measuring the
quantity of work. This is taken care in pricing of the different masonry
works. Each type of masonry works are measured separately into categories
to calculate exact cost of construction based on its price.
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Rules for Measurement of Masonry Works:
Following are the general rules for measuring masonry works:
1. Masonry is measured as “net in place” with deductions for openings such
as doors, windows, ventilation etc.
2. Different shapes of masonry units are measured separately such
rectangular, circular etc.
3. Masonry at different heights are measured separately because masonry at
higher elevation from ground may require scaffolding and hoisting.
4. Masonry work is measured separately in the different categories such as:
a) Facings
b) Backing to facings
c) Walls and partitions
d) Furring to walls
e) Fire protection
5. Masonry work which requires cleaning of surface are measured in area
such as square meter or square feet.
6. Any special treatment to masonry surfaces are measured in area such as
square feet or square meter, with the count of number of coats applied.
7. Any joints in masonry structure such as expansion joints or control joints
are measured in length such as meter or feet with description of type of
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joint. Also the type of joint filler material for the joint used is indicated in
description.
8. For different types of mortar, or mortar with different types of admixtures
are measured separately. These are measured in volume such as cubic
meter or cubic feet.
9. If any reinforcement is used in masonry, then it is measured separately.
10. Extra items in masonry construction such as anchor bolts, sleeves,
brackets, and similar items that are built into masonry are described in the
measurement and measured separately.
11. Enumerate weep holes where they are required to be formed using
plastic inserts and such like.
12. Measure rigid insulation to masonry work in square feet or square
meters, describing the type and thickness of material.
Measurement of Brick Masonry
For measurement of brick masonry, general rules specified above are used
along with following points:
1. Brick masonry is measured in volume for thickness more than single
bricks. For masonry with single bricks, it is measured in square
meters.
2. Facing bricks are measured separately.
3. Different types or class of brick masonry are measured separately.
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Measurement of Concrete Block Masonry
Concrete block masonry are measured as general rules described above
along with following points:
1. Different types of concrete block masonry such as type and size of
concrete blocks are measured separately.
2. Special units required at corners, jambs, heads, sills, and other
similar locations are measured separately.
3. Measure concrete to core fills and bond beams in cubic feet or cubic
meters, stating the strength and type of concrete to be used. These
are measured separately for different types of concrete block based
on strength.
4. Measure in linear feet or meters reinforcing steel to core fills and
bond beams, stating the size and type of rebar to be used.
Deduction for Openings and Bearings in
Masonry Works Measurements
No deduction is made for following:
(1) Opening each up to 1000sq cm 0.1 square meter
(2) Ends of beams, post, rafters, etc. up to 500 sq.cm or 0.05 sq.m in
section.
(3) Bed plate, wall plate, bearing of balcony (chajja) and the like up to 10
cm depth. bearing of floor and roof slabs are not deducted from masonry.
For other openings deduction are made in following manner:
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Deductions for Rectangular Opening:
Full deduction is made for rectangular openings in masonry walls
Deductions = L x H x thickness of wall
Deductions for Reinforced Concrete and Reinforced
Brickwork:
Reinforced concrete and reinforced brickwork may be in roof or floor slab, in
beam lintel, column, foundation etc and the quantities are calculated in cubic
meter. Length, breadth and thickness are taken correctly from the plan,
elevation and section or from other detailed drawings.
The quantities are calculated in cubic meter exclusive of steel reinforcement
and its bending but inclusive of centering and shuttering and fixing and
binding reinforcement in position. The reinforcement including its bending is
taken up separately under steel work in as per weight.
For this purpose, 0.6% to 1% (usually 1%) of R.C.C. or reinforced brickwork
by volume may be taken for steel if other details are not available. The
volume of steel is not required to deducted from R.C.C. or reinforced brick
work.
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Reinforced concrete and reinforced brickwork may also be estimated
inclusive of steel and centering and shuttering for the complete work, if
specified. Centering and shuttering are usually included in the R.C.C or R.B.
work but may also be taken separately as per square meter of surface in
contact with concrete.
Deductions for Flooring and Roofing Works:
Ground floor:
The base line concrete and floor finishing of cement concrete or stone or
marble or mosaic etc. are usually taken as one job or one item and the
quantity is calculated in square meter multiplying the length by the breadth.
The length and breadth are measured as inside dimensions from wall to wall
of superstructure. both the work of base concrete and floor finishing are paid
under one item.
Roof:
Supporting structure is taken separately in cubic meter and the lime
concrete terracing is computed in square meter with thickness specified
under a separate item including surface rendering smooth. The compacted
thickness of lime concrete terracing is 7.5 cm to 12 cm average. Lime
concrete terracing may also be calculated in cubic meter with average
thickness.
Plastering:
Plastering usually 12mm thick is calculated in square meter. for wall the
measurement are taken for whole face of the wall for both side as solid, and
deducting for opening are made in following manner.
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(1) No deduction is made for the end of beams, posts, rafters etc.
(2) For small opening up to 0.5 square meter no deduction is made, and at
the time no additions are made for jambs, soffits and sills of these opening.
(3) For opening exceeding 0.5 square meter but not exceeding 3 square
meter deduction is made for one side and other face is allowed for jambs
soffits and sills which are not taken into account separately
(4) For opening above 3 square meter deduction is made for both faces of
the opening and the jambs, soffits and sills are into account and added.
Pointing:
Pointing in wall calculated in square meter for whole surface and deduction
similar to plastering is made.
Cornice:
Ornamental and large cornice is measured in running meter or running foots
for the complete work which includes masonry, plastering, moldings etc. and
paid for in running meter.
Similarly, string course, corbelling, coping etc are measured and paid for in
running meters for the complete work.
Pillars:
Pillars are taken separately in cubic meter foe their net volume and
quantities are calculated.
Wood Works:
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Wooden beams, posts, wooden roof trusses, doorpost etc. come under this
items and the quantities are computed in cubic meter. The dimension of
finished work shall be taken.
Iron Works:
This computed weight in kg or quintal and the quantities are calculated
correctly by multiplying the weights per running meters by length. the
weight per running meter can be obtained from the steel section book. For
steel joint the length is equal to the clear span plus two bearing the bearing
may taken third forth thickness of wall or 20 to30 cm.
White Wash or Color Washing or Distempering:
The quantities are computed in square meter and are usually same as for
plastering. The inside is usually white washed or distempered and this item
will be same as for outside plaster. These item need not be calculated
separately but simply written as same as for outside plaster and inside
plaster.
Brick calculator | Brickwork calculation and brick
estimation
In this article i will tell you how to calculate bricks in a wall. By the explanation
describe below, you can make your own MS Excel Brick calculator program to
calculate bricks in a wall.
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1. We know that standard dimensions of brick is 9 inch x 3 inch x 4.5 inch.
2. Convert these dimensions into feet.
3. Now multiply these dimensions to get volume of a brick.
4. 0.75 feet x 0.25 feet x 0.375 feet = 0.0703125 cubic feet.
5. Bricks required for 1 cubic feet brickwork will be (1/0.070) = 14.285 bricks
6. 10% space of brickwork is covered by mortar.
7. Subtract 10% bricks from 14.285, 14.285-1.4285=12.85 bricks.
8. Add 5% wastage of bricks.
9. 5% of 12.85 is 0.64 bricks.
10.Add 0.64 and 12.85 to get number of bricks in 1 cubic feet, we get 0.64 + 12.85
=13.492 bricks or we can say that 13.5 bricks.
Number of bricks in 100 Cubic feet brickwork
As we know that there are 13.5 bricks in 1 cubic feet. So in 100 cubic feet
there will be 1350 bricks.
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Bricks per square foot
Wall thickness Bricks per square foot
4.5 inch 5.0625 bricks
9 inch 10.125 bricks
13.5 inch 15.1875 bricks
Bricks per square meter
Wall thickness Bricks per square meter
4.5 inch 57.16 bricks
9 inch 114.329 bricks
13.5 inch 171.49 bricks
How to calculate bricks in a wall ?
To calculate bricks in a wall, we need to know the dimensions of the wall. For instance,
if a wall is 10 feet long with 10 feet height and 9 inch thickness. Then we can find its
bricks in a following way. Multiply dimensions of wall. 10 feet x 10 feet x 0.75 feet. We
will get 75 cubic feet. We have seen above that there are 13.5 bricks in 1 cubic feet
brickwork. So there will be 75 x 13.5 =1012.5 bricks in 75 cubic feet. In this way we
calculate bricks in any wall with the known dimensions.
Bricks calculation formula
Bricks calculation formula is written below.
In feet
 Length of wall in feet x height of wall in feet x thickness of wall in feet x
13.5 = number of bricks
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In meter
 length of wall in meter x height of wall in meter x thickness of wall in
meter x 500 = number of bricks
Number of bricks in 1 Cubic meter brickwork
Standard dimensions of brick in metric units are 225 x 112.5 x 75 mm.
1. multiply these dimensions to get volume of a brick, 0.225 m x 0.1125 m x 0.075
m=0.00189 cubic meter.
2. In one cubic meter, number of bricks will be (1/0.00189)=529.1 bricks.
3. 10% of brickwork will be covered by mortar.
4. Subtract 10% bricks from the 529.1, we will get 529.1-52.91=476.20 bricks.
5. Add 5% wastage of bricks.
6. 5% of 476.20 is 23.80 bricks.
7. Add 23.80 and 476.20 to get number of bricks in one cubic meter brickwork.
8. 23.80+476.20=500 bricks.
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Standard conversion factors
INCH = 25.4 MILLIMETRE
FOOT = 0.3048 METRE
YARD = 0.9144 METRE
MILE = 1.6093 KILOMETER
ACRE = 0.4047 HECTARE
POUND = 0.4536 KILOGRAM
DEGREE FARENHEIT X 5/9 – 32 = DEGREE CELSIUS
MILLIMETRE= 0.0394 INCH
METRE = 3.2808FOOT
METRE = 1.0936YARD
1) MILD STEEL (MS)
SHEET
WEIGHT (KGS) = LENGTH (MM) X WIDTH (MM) X 0. 00000785 X THICKNESS
example – The weight of MS Sheet of 1mm thickness and size 1250 MM X 2500 MM shall be
2500MM X 1250 MM X 0.00000785 X 1 = 24.53 KGS/ SHEET
ROLLED STEEL CHANNELS
MS SQUARE
WEIGHT (KGS ) = WIDTH X WIDTH X 0.00000785 X LENGTH.
Example : A Square of size 25mm and length 1 metre then the weight shall be.
25x25X 0.00000785 X 1000mm = 4.90 kgs/metre
MS ROUND
WEIGHT (KGS ) = 3.14 X 0.00000785 X ((diameter / 2)X( diameter / 2)) X LENGTH.
Example : A Round of 20mm diameter and length 1 metre then the weight shall be.
3.14 X 0.00000785 X ((20/2) X ( 20/2)) X 1000 mm = 2.46 kgs / metre
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SS ROUND
DIA (mm) X DIA (mm) X 0.00623 = WEIGHT PER METRE
SS / MS Pipe
OD ( mm) – W.Tthick(mm) X W.Thick (mm) X 0.0248 = Weight Per Metre
OD ( mm) – W.Tthick(mm) X W.Thick (mm) X 0.00756 = Weight Per Foot
SS / MS CIRCLE
DIA(mm) X DIA (mm) X THICK(mm) 0.0000063 = Kg Per Piece
SS sheet
Length (Mtr) X Width (Mtr) X Thick(mm) X 8 = Weight Per Piece
Length (ft) X Width (ft) X Thick(inch) X 3 /4 = Weight Per Piece
S.S HEXAGONAL BAR
DIA (mm) X DIA (mm) X 0.00680 = WT. PER Mtr
Dia (mm) X Dia (mm) X 0.002072 = Wt. Per foot.
BRASS SHEET
WEIGHT (KGS) = LENGTH (MM) X BREADTH (MM) X 0. 0000085 X THICKNESS
Example – The weight of brass sheet of thickness 1 mm, length 1220mm and breadth 355mm
shall be
1220 X355X 0.0000085 X 1 = 3.68 Kgs/Sheet
Following table shows how can we convert various most commonly used units from one unit
system to another.
Units to convert Value
Square foot to Square meter 1 ft² = 0.092903 m²
Foot per second squared to Meter per
second squared
1 ft² = 0. 3048 m²
Cubic foot to Cubic meter 1 ft³ = 0.028316 m³
Pound per cubic inch to Kilogram per
cubic meter
1 lb/in³ = 27679.9 047102 kg/m³
Gallon per minute = Liter per second 1 Gallon per minute = 0.0631 Liter per second
Pound per square inch = Kilopascal 1 Psi (Pound Per Square Inch) = 6.894757 Kpa
(Kilopascal)
Pound force = Newton 1 Pound force = 4.448222 Newton
Pound per Square Foot to Pascal 1 lbf/ft2 = 47.88025 Pascal
Acre foot per day = Cubic meter per
second
1 Acre foot per day= 1428 (m3/s)
Acre to square meter 1 acre = 4046.856 m²
Cubic foot per second = Cubic meter per
second
1 ft³/s = 0.028316847 m³/s
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Measurement units and standards are different in different countries but to maintain a
standard, SI units are mostly used when dealing with projects involving different countries or
even different states. Small projects can be done with the locally used unit system but when
the project is big, one standard unit system is to be used.
Two most common system used in the United States are
 United States Customary System (USCS)
System International (SI)
But the SI unit system is more widely used all over the world. Following is the table which
shows how you can convert USCS measurements in SI measurements. ( Just multiply the USCS
amount with the corresponding figure given in table below
Convert USCS into SI Units
USCS unit X Factor = SI unit SI symbol
Square foot X 0.0929 = Square meter M2
Cubic foot X 0.2831 = Cubic meter M3
Pound per square inch X 6.894 = Kilopascal KPa
Pound force X 4.448 = Newton Nu
Foot pound torque X 1.356 = Newton meter N-m
Kip foot X 1.355 = Kilonewton meter LN-m
Gallon per minute X 0.06309 = Liter per second L/s
Kip per square inch X 6.89 = Megapascal MPa
BASIC STANDARDS:
1 inch = 25.4 millimeters = 2.54cm.
1 meter = 39.37 inches =1.09 yards.
1 liter = 0.22 galls (imp.)
1 gallon (imp.) = 4.546 liters.
1 gallon (US) = 3.785 liters.
1 Kilogram (kg) = 2.2046 pounds (lb).
METRIC UNIT OF WEIGHT/MASS:
1 tonne = 1000 kilograms = 1,000,000 grams.
1 quintal = 100 kilograms = 100,000 grams.
1 Slug = 14.606 kg
1 Slug = 32.2 lb
MEASUREMENTS OF LENGTH:
1 foot = 12 inches.
1 yard = 3 feet.
1 furlong = 220 yards.
1 mile = 8 fulongs.
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1 Kilometer (Km) = 1000 meters.
1 meter (m) = 100 centimeters (cm).
1 cm = 10 millimeter (mm).
METRIC UNITS FOR LIQUID MEASUREMENTS:
1 liter = 1000ml.
1 liter = 1kg.
1 kiloliter (1000 liters) = 1 cubic meter/ 1 cu.m/ 1 m3.
CONVERSION FACTORS:
1 cu. ft. = 28.317 liters.
1 cu. ft. = 0.028 cu. meters.
1 cu. ft. = 6.24 galls (imperial).
1 cu. ft. = 7.48 galls (US).
1 imp. gall = 1.20 galls (US), liquid.
1 imp. gall = 1.03 galls (US), dry.
MEASUREMENTS OF AREA:
1 Acre = 43560 sq. ft
1 Acre = 4046.46 sq. m
1 Acre = 8 Kanals.
1 Kanal = 20 Marlas.
1 Marla = 225 sq. ft (* in some regions 272 sq. ft)
1 Marla = 15.50 sq.m
MISCELLENIUS CONVERSION FACTORS:
1 cu.m = 35.32 cu.ft.
1 Pound = 4.448 Newton (Force).
1 klb = 4.448 kN.
1 Psi (lb/sq.in) = 6.689 Pascal (N/sq.m)
1 (lb/sq. ft) = 0.048 (kN/sq.m)
CALCULATION OF UNIT WEIGHT OF STEEL BARS:
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After estimating it is very important to know the unit weight of steel bars because, we estimate
as 100 meter 20mm ø bar or 100 feet 16mm ø bar, etc (ø is the symbol of diameter).
But steel bar suppliers will not understand this notation, they measure the steel bars in weight.
So we have to order them in kg or quintal or ton. In this article, we will discuss how to calculate
unit weight of steel bars of different diameter.
The formula is W = D²L/162
Where
W = Weight of steel bars.
D = Diameter of steel bars in mm.
L = Length of bars in meter.
Example 1: Calculate the weight of 60 meters long 12 mm ø bar.
Here, D = 12 mm.
L= 60 m.
We know that, W = D²L/162
W = 12² x 60/162 = 53 kg
Weight of 60 m 12mm ø bar is 53 kg.
Let’s look for another example.
Example 2: Calculate the weight of 100 m 16 mm ø bar.
Here, D = 16 mm.
L = 100 m.
W = 16² x 100/162 = 158 kg.
If we put 1 meter length for each diameter of steel bar in the formula then we will get the unit
weight.
 10mm ø bar = 10² x 1/162 = 0.617 kg/m
 12mm ø bar = 12² x 1/162 = 0.888 kg/m
 16mm ø bar = 16² x 1/162 = 1.580 kg/m
 20mm ø bar = 20² x 1/162 = 2.469 kg/m
If we multiply the length of bars with this unit weight we will get the total weight of steel bars.
For example, total weight of 1000 meter long 20mm ø steel bar is,
1000 x 2.469 = 2469 kg.
Using the same method we can calculate the unit weight of different steel bars.
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Here I have calculated in meter but we can also calculate in foot. To calculate in foot we have to
use the following formula:
W= D²L/533
Where D = Diameter of bars in mm.
L = Length of bars in foot.
HOW TO CALCULATE STEEL QUANTITY FOR RCC
BEAM, COLUMN AND SLAB
Following are the steps to calculate the quantity of steel for RCC slab
1. Prepare a bar bending schedule in order to classify different shapes of bars (bent up bar,
straight anchor bar, eos bar, curtail bar etc) and diameters.
2. List down all the shapes of bars from the drawing.
3. Count the number of bars of each of those shapes.
4. Then calculate the cutting length of each of those bars.
Cutting length of bar = (length of the member – deduction for cover on both
sides) + development length.
5. Then calculate the unit weight of each dia bars by the following formula:
W = d^2/162
Where d is the dia in mm and weight (w) in kg.
6. Then calculate weight of rebar
Weight of rebar= no of bars x cutting length x unit weight
7. Add all the weight to get the total steel quantity.
NOTE – 1. Minimum % of steel as per Indian standard are:
1. Beam (Teinsion reinforcement):
As = 0.85bd/fy of gross cross-section area.
2. Slab – 0.12% of total area
3. Column – 0.8% of cs area
2. Maximum % steel as per Indian standard are:
Beam – 4 % of cross-section area.
Slab – 4% of cross-section area.
column — 6% of cross-section area.
3. . Development Length is usually specified in the drawings, but if not thenyou can calculate it
as,
D.L = Depth – 2 times cover
4. Binding wire = 10 grams per kg of reinforcement.
5. No. of stirrups = (length of member – 2 x cover ) / spacing + 1
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WHAT IS BAR BENDING SCHEDULE?
Bar bending schedule commonly known as BBS is one of the most important terms in Civil
Engineering. Because it plays a vital role in building construction.
Like other building materials estimation of steel is also required for constructing a building and
here BBS comes with an easy solution. Bar bending schedule provides the reinforcement
calculation and some other important details such as bar mark, bar diameter, bar shape, cutting
length, number of bars, the weight of bar, total weight of steel etc. So that we can order the
required amount of steel in advance.
HISTORY OF BAR BENDING SCHEDULE:
Long years back when there was no today’s bar bending schedule, certain recommendations
given by Prof. BN Dutta were used for estimating steel for different components of a building.
But these are now backdated (not wrong) and we don’t use them in today. Because No
accurate values were specified if we use more bars in a single member. Nowadays we are
constructing 150+ floors building. It is now possible with our modern techniques, equipment
etc. Estimation of steel becomes easier because of BBS.
Civil engineers who are working on site or freshers who are going to work at construction sites
must know how to prepare bar bending schedule. In this article, I will discuss some important
things used in preparing bar bending schedule.
These are just the basic things. In future, I will come up with some other articles related to BBS
such as BBS for beams, columns, slabs, footings etc.
HOOK LENGTH:
The hook is the extra length left at the 4th corner of a stirrup so that the stirrup retains its
shape.
Generally, hook length is taken as 9d for one side.
Where d = Diameter of the bar.
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The total length of stirrups = Total length of the bar + 2 x hook length (for two hooks)
= L + 2 x 9d
= L + 18d.
Where L = length of the bar for stirrup.
BEND LENGTH:
The bar is bent at the column end to tie with the footings. This extra length for bend is called
bend length.
Bend length is generally considered as 16 d
Bend Length = 16d
DEVELOPMENT LENGTH:
Development length is the length of bar required for transferring the stress into concrete.
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In simple words, the quantity of the rebar length that is actually required to be embedded into
the concrete to create the desired bond strength between steel and concrete and furthermore
to produce required stress for the steel in that area.
The formula for development is given below:
Development length (Ld) = d x σs/τbd
Where
d = Diameter of the bar.
σs = Stress in the bar at the section considered as design load
τbd = Design bond stress.
LAP LENGTH:
Lap length is the overlapping length of two bars side by side which gives required design length.
In RCC structure if the length of a bar is not sufficiently available to make design length, lapping
is done.
Suppose we need to build a 20 m tall building. But is there any 20 m bar available in the
market? No, the maximum length of rebar is usually 12 m, so we need to join two bars to get 20
m bar.
Lap length for tension members = 40d
Lap length for compression members = 50d.
d = Diameter of bars.
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Look at the image below. You may be seen this on the terrace (top floor) of buildings. This extra
rebar is left for future construction purpose. I hope you understand this.
CRANK LENGTH:
Generally, bars are bent near the support at an angle of 45°. The angle of bend may also be 30°
in shallow beams. The purpose of bend near the support is firstly to resist the negative bending
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moment which occurs in the region of the support and secondly to resist the shear force which
is greater at the support.
Crank bars are mostly provided in slabs.
Crank length = D/sin45° – D/tan45° =1.42D – D = 0.42D
So Crank Length = 0.42D
Where D = Clear height of the bar = Thickness of slab – (Top cover + Bottom cover) – Diameter
of the bar
UNIT WEIGHT OF STEEL:
The weight of bar is calculated by the following formula
W = d²L/162
Where W = Weight of bars.
L = Length of bars in meter.
d = Diameter of the bar.
Example: Calculate the weight of 20 meters long 16 mm ø bar
W = 16² x 20/162 = 32 kg.
CUTTING LENGTH OF BENT UP BARS IN SLAB:
As a site engineer, you need to calculate the cutting length of bars according to the slab
dimensions and give instructions to the bar benders.
For small area of construction, you can hand over the reinforcement detailing to the bar
benders. They will take care of cutting length. But beware, that must not be accurate. Because
they do not give importance to the bends and cranks. They may give some extra inches to the
bars for the bends which are totally wrong. So it is always recommended that as a site engineer
calculate the cutting length yourself. In this article, we will discuss how to the calculate length
for reinforcement bars of slab. Let’s start with an example.
EXAMPLE:
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Where,
Diameter of the bar = 12 mm
Clear Cover = 25 mm
Clear Span (L) = 8000
Slab Thickness = 200 mm
Development Length(Ld) = 40d
CALCULATION:
Cutting Length = Clear Span of Slab + (2 x Development Length) + (2 x inclined length) – (45°
bend x 4) – (90° bend x 2)
Inclined length = D/(sin 45°) – dD/ (tan 45°) = (D/0.7071) – (D/1)= (1D – 0.7071D)/0.7071= 0.42
D
As you can see there are four 45°bends at the inner side (1,2,3 & 4) and two 90° bends ( a,b ).
45° = 1d ; 90° = 2d
Cutting Length = Clear Span of Slab + (2 X Ld) +(2 x 0.42D) – (1d x 4) – (2d x 2) [BBS Shape
Codes]
Where,
d = Diameter of the bar.
Ld = Development length of bar.
D = Height of the bend bar.
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In the above formula, all values are known except ‘D’.
So we need to find out the value of “D”.
D = Slab Thickness – (2 x clear cover) – (diameter of bar)
= 200 – (2 × 25) – 12
= 138 mm
Now, putting all values in the formula
Cutting Length = Clear Span of Slab + (2 x Ld) +(2 x 0.42D) – (1d x 4) – (2d x 2)
= 8000 + (2 x 40 x 12) +(2 x 0.42 x 138) – (1 x 12 x 4) – (2 x 12 x 2)
∴ Cutting Length = 8980 mm or 8.98 m.
So for the above dimension, you need to cut the main bars 8.98 m in length.
BAR BENDING SCHEDULE OF LINTEL BEAM:
In this article, I will discuss how to prepare BBS of RCC Lintel Beam.
1. Calculate Total Length Of Main Bars:
Length of 1 bar = Length of lintel – clear cover for both sides
= 2500 – 2 x 25 [Clear cover for both sides]
=2450 mm
= 2.4 m.
Length of 4 bars = 2.4 x 4 = 9.6 m
2. Calculate Weight Of Steel For Main Bars:
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Weight of steel for 12 mm bar = D²L/162 = 12² x 9.6/162 = 8.53 kg.
3. Calculate No Of Stirrups:
No of stirrups = (Total length of lintel/c/c distance between strriups) + 1
= (2500/150) + 1 = 18
4. Calculate Total Length Of Stirrups:
Inner depth distance = 150 -25 -25 -8 =84 mm
Width distance = 150 – 25 – 25 -8 = 84 mm.
Cutting length of stirrups =(2x Inner deoth diatance) +(2xWidth depth) + Hooks Length – Bend
Hooks length = 10d
Bend = 2d
We have 2 hooks and 5 bend
So,
Cutting length of stirrups = (2×84) + (2 x84) +2x10x8 -5x2x8 = 418 mm = 0.418 m
Total length of stirrups = 0.418 x 18 = 7.54 m
5. Calculate Weight Of Steel For Stirrups:
Weight of steel for stirrups = D²L/162 = 8² x 7.54/162 = 7.61 kg.
Total weight of steel for lintel = 8.53 + 7.61 = 16.14 kg.
THE FORMULA D²L/162 FOR CALCULATING WEIGHT OF STEEL BARS
FULLY DERIVED
THE FORMULA D²L/162 FULLY DERIVED:
To calculate the weight of steel bars you must use the formula D²L/162, but do you know where
the formula D²L/162 came from? Okay, no problem if you don’t know. In this article, I will share
how to derive the formula D²L/162. So let’s start from the beginning.
The formula is D²L/162
Where,
D = Diameter of steel bar in millimeter
L = Length of steel bars in meter
Calculation Of The Formula D²L/162:
We know that,
Weight= Cross sectional area x Length x Density
For steel bar, this also remains same.
The weight of steel bars= Cross sectional area of steel bar x Length of steel bar x Density of steel
bar.
That means,
W = A x L x ρ
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Where,
W = Weight of steel bars
A = Area = πD²/4
π (pi) = 3.14
D = Diameter of steel bar in millimeter
L = Length of steel bar in meter
ρ (Rho) = Density of steel bar = 7850 kg/m³
Therefore,
W = 3.14 x D²/4 x L x 7850
But there is two conflicting unit in the formula. Which is millimeter for D and meter for ρ (Rho).
So we need to convert either D or ρ to the same unit.
Let’s change the unit of D from millimeter to meter.
1 millimeter = 0.001 meter
Let’s put this into the formula,
W= 3.14 x {(D² x 0.001 x 0.001)/4} x L x 7850
= D²L/162
Hope you all understood this calculation. Using this formula we can easily calculate the weight
of steel bars.
10 + THUMB RULES FOR CONCRETE MIX
DESIGN
FOR ADDING 4 LITERS OF WATER IN 1 CU.M FRESHLY MIXED CONCRETE
1. The slump value will be increased by 25 mm.
2. The compressive strength of concrete will be decreased by 1.5 to 2.0 N/mm2
3. The shrinkage potential will be increased by 10%.
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4. 1/4 bag of cement will be wasted.
IF THE TEMPERATURE OF FRESHLY MIXED CONCRETE IS INCREASED BY 1%, THEN
1. 4 liters of water per cu.m will give equal slump.
2. The air content will be decreased by 1%.
3. The compressive strength of concrete will be decreased by 1.0 to 1.5 N/mm2.
IF THE AIR CONTENT OF FRESHLY MIXED CONCRETE IS
1. Increased by 1% then the compressive strength will be decreased by 5 %.
2. Decreased by 1%, yield will be decreased by 0.03 cu.m per 1 cu.m.
3. Decreased by 1%, then the slump value will be decreased about 12.5 mm.
4. Decreased by 1%, then the durability of the concrete will be reduced by 10%.
CALCULATION OF MATERIALS FOR DIFFERENT MIX RATIO:
Quantity estimation of materials is essentially required in any construction works and quantity
of materials depend on the mix proportions of the concrete. In our previous article, we have
already discussed how to calculate bricks in a wall. Today we will discuss how to calculate
quantities of materials for different mix ratio of concrete. (Dry mix method)
We will calculate quantities of materials for 1 m3 concrete (By volume).
Let us assume the mix proportion is 1 : 2: 4 (cement:sand:stone =a:b:c)
Volume of wet concrete = 1 m3
Volume of dry concrete = 1 × 1.54 = 1.54 m3
What Is 1.54 Given Below:
CALCULATION FOR CEMENT:
Formula, Cement = (Volume of dry concrete/a+b+c) × a
= (1.54/a+b+c) × a = [(1.54/1+2+4)] × 1 = 0.22 cum
Now density of cement = 1440 kg/cum
∴ Volume of cement = 0.22 × 1440 =316.8 kg.
As we know, 1 bag of cement contains 50 kg of cement .
∴ Cement bags required = 316.8/50 = 6.33 bags.
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CALCULATION FOR SAND:
Formula, Sand = (Volume of dry concrete/a+b+c) × b
= (1.54/a+b+c) × b = (1.54/1+2+4) × 2 = 0.44 cum.
CALCULATION FOR STONE CHIPS:
Formula, Stone Chips = (Volume of dry concrete/a+b+c) × c
= (1.54/a+b+c) ×c = (1.54/1+2+4) × 4 = 0.88 cum.
CALCULATION FOR WATER CONTENT:
Let us assume the water/cement ratio of the concrete is 0.45.
w/c = 0.45
Required water for 1 bag cement = 0.45 × 0.0353 = 0.0159 cum.
Where volume of 50 kg cement = 0.0353 cum
1 m3 water = 1000 Litre
Required water for 1 bag cement=0.0159 × 1000 = 15.9 Litre.
∴ Required water for 6.33 bags cement = 6.33 × 15.9 = 101 Litre.
SUMMARY:
Cement = 6.33 bags.
Sand = 0.44 cum
Stone chips = 0.88 cum
Water = 101 litre.
Note: Yield of concrete is considered as 67% & Wastages of materials = 2%
You can use the same formula for different mix proportions such as 1:1.5:3 etc.
Here, we have used cubic meter unit but you can also calculate in cubic feet unit.
UNIT WEIGHT OF BUILDING MATERIALS
Unit Weight Of Building Materials:
There are many building materials used in construction. In the below table we have tried to
cover the unit weight of building materials which are most commonly used at the construction
site.
Material Unit Weight
Water 1000 Kg/ m3
Bricks (broken) 1420 Kg/ m3
Bricks(common) 1600 Kg/ m3
Cement(ordinary) 1440 Kg/ m3
Cement (rapid hardening) 1250 Kg/ m3
Cement Mortar 2000 Kg/ m3
Cement Concrete (Plain) 2400 Kg/ m3
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Cement Concrete (Reinforced) 2500 Kg/ m3
Glass 2500 Kg/ m3
Lime Concrete 1900 Kg/ m3
Cement Plaster 2000 Kg/ m3
Lime Plaster 1700 Kg/ m3
Stones (Ballast) 1720 Kg/ m3
Stones (Aggregates) 1750 Kg/ m3
Stones (Basalt) 2850 Kg/ m3
Stones (Granite) 2450 Kg/ m3
Stones (Marble) 2650 Kg/ m3
Timber (Oak, Sal) 510 Kg/ m3
Timber (Mango) 650 Kg/ m3
Timber (Teak) 625 Kg/ m3
Coal 600 Kg/ m3
Plastics 1250 Kg/ m3
Oils 800 Kg/ m3
Ashes 650 Kg/ m3
Clinker 750 Kg/ m3
Rubber 1300 Kg/ m3
Slag 1500 Kg/ m3
Clay Soil 1900 Kg/ m3
Sand (dry) 1540 to 1600 Kg/ m3
Sand (wet) 11760 to 2000 Kg/ m3
Steel 7850 Kg/ m3
Chalk 2100 Kg/ m3
Bitumen 1040 Kg/ m3
CALCULATION OF BRICKS IN A WALL
Estimation of building materials is essentially required before starting a new construction
project. In our previous article, we have already discussed how to calculate cement, sand, and
aggregates. Today we will discuss the easiest method to calculate the required number of bricks
in a wall. So let’s start from the beginning.
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REQUIRED DATA:
1. Volume of the wall.
2. Volume of a standard brick.
3. Details of openings in the wall.
PROCEDURE:
1. First, calculate the volume of the wall to be built:
Let us assume,
The length of the wall (l) = 10 foot.
The height of the wall (h) = 10 foot.
Thickness of the wall (b) = 1 foot.
Calculate the volume of the wall by multiplying the length, height, and thickness.
∴ Volume of the wall = l×h×b = 10×10×1 =100 Cu.F
2. Calculate the volume of the brick:
The standard size of a brick (IS Standard) is 190 mm ×90 mm ×90 mm and
with the mortar joint, it becomes 200mm × 100 mm× 100 mm.
l = 200 mm= 0.656168 ft.
b = 100 mm =0.328084 ft.
h = 100 mm = 0.328084 ft.
∴ Volume of the brick = l× b×h = 0.656168× 0.328084× 0.328084 = 0.0706 Cu.F
3. To find out the total nos of brick divide the volume of wall by the volume of the brick.
∴ No. of bricks required = 100/0.0706 = 1416 no. of bricks.
Note: 1. Consider 10% wastages of bricks.
2. If the wall has any openings such as doors, windows etc subtract the volume of the openings
from the volume of wall and then divide it by the volume of brick.
HOW TO CALCULATE NUMBER OF CONCRETE
BLOCKS IN A WALL
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Concrete Block Wall
NUMBER OF CONCRETE BLOCKS IN A WALL:
There are several methods for calculating number of blocks in a wall. In this article, I will explain
two simple methods to find out total no. of blocks for a wall.
 Surface area method.
 Volume method.
PROCEDURE:
1. CALCULATION BY SURFACE AREA METHOD:
REQUIRED DATA:
1. Surface area of the wall.
2. Surface area of a standard concrete block.
3. Surface area of openings in the wall.
STEP 1:
Determine The Length & Height Of The Wall:
Let, the Length of the wall = 10 feet.
The height of the wall = 10 feet.
STEP 2:
Calculate The Surface Area Of The Wall:
We know, Surface Area = Length x Height
∴ Surface area of the wall = 10 x 10 = 100 sq. feet.
STEP 3:
Calculate The Surface Area Of Openings:
If the wall has any openings such as door, windows etc, calculate the surface area of openings.
Let the wall has a window of 3′ x 3′
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∴ Surface area of the window = 3 x 3 =9 sq. ft
STEP 4:
Substract The Surface Area Of Openings From Surface Area Of Walls:
∴ Final Surface Area of wall = 100 – 9 = 91 sq.ft.
STEP 5:
Calculate The Surface Area Of A Concrete Block With Mortar Allowance:
Let the block is 16″ x 8″ x 8″ and mortar allowance is 1″
∴ Surface Area of one block with mortar = (16+1) x (8+1)= 153 inch²
= 153/12×12 = 1.0625 sq.ft
STEP 6:
Divide The Total Surface Area Of The Wall By Surface Area Of One Block:
∴ Number of blocks = Surface Area of wall/Surface Area of a block = 91/1.0625 = 86
Consider 5% wastage of concrete blocks.
So the total numbers of blocks required = 86 + (86 x 5/100) = 86 + 4 = 90.
2. CALCULATION BY VOLUME METHOD:
REQUIRED DATA:
1. Volume of the wall.
2. Volume of a standard concrete block.
3. Volume of openings in the wall.
STEP 1:
Determine The Width, Height, And Thickness Of The Wall:
Let, the width of the wall = 10 feet.
The height of the wall = 10 feet.
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The thickness of the wall = 8″ = 0.67 feet. [ Thickness of wall will be same as the thickness of
one concrete block]
STEP 2:
Calculate The Volume Of The Wall:
We know, Volume = Width x Height x Thickness
∴ Volume of the wall = 10 x 10 x 0.67 = 67 cubic feet.
STEP 3:
Calculate The Volume Of Openings:
If the wall has any openings such as door, windows etc, calculate the volume of openings
Let the wall has a window of 3′ x 3′ x 0.67′ [ Thickness of the window will be same as the
thickness of the wall]
∴ Volume of the window = 3 x 3 x 0.67 =6 cu. ft
STEP 4:
Substract The Volume Of Openings From Volume Of Walls:
∴ Final volume of wall = 67 – 6 = 61 cu.ft.
STEP 5:
Calculate The Volume Of A Concrete Block With Mortar Allowance:
Let the block is 16″ x 8″ x 8″ and mortar allowance is 1″
∴ Volume of one block with mortar = (16+1) x (8+1) x 8 = 1224 inch3 [The mortal will be given
on the upper side and one side of every concrete block]
= 1224/12x12x12 = 0.70 cu.ft
STEP 6:
Divide The Total Volume Of The Wall By Volume Of One Block:
∴ Number of blocks = Volume of wall/Volume of a block = 61/0.70 = 86
Consider 5% wastage of concrete blocks.
So the total numbers of blocks required = 86 + (86 x 5/100) = 86 + 4 = 90.
Note:
If the wall does not have any opening skip step 4, and just divide the surface area of wall by the
surface area of one block.
HOW TO CALCULATE QUANTITY OF
MATERIALS IN ARCH
In this article, I will discuss how two calculate quantity of materials in arch.
1. SEMI CIRCULAR ARCH:
Given:
Span = 8 ft
Height = 4 ft
Thickness = 1 ft
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Breadth = 1ft
To calculate the quantity of materials in semi circular arch we need to calculate the volume of
arch.
Volume of arch = Cross-section of arch x Arch length
We know Cross-section area = Thickness of arch x Breadth of arch = T x B
From the above image, you can see the thickness and breadth are 1 ft.
Cross-section of arch = 1 x 1 = 1 ft²
Now Arch length = Circumference of half circle (The arch is semi circular)
We know circumference of circle = 2πR
Circumference of half circle = 2πR/2 = πR
We don’t what is R. So we need to find out the ‘R’.
R = Half span + Thickness/2 = 4 +1/2 = 4.5 ft.
Arch length = πR =3.14 x 4.5 = 14.13 ft.
Quantity of materials in arch = 1 x 14.13 = 14.13 cft.
2. SEGMENTAL ARCH:
Given:
Span = 8 ft
Height = 2ft
Thickness = 1 ft
Breadth = 1ft
Central angle = 105°
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SOLUTION:
Volume arch = Cross-section of arch x Arch length
We know Cross-section area = Thickness of arch x Breadth of arch = T x B
Arch length = θπR/180
Now R = (a² + h²)/2h [a =half span = 8/2 =4]
=(4² + 3²)/2 x 3 = 25/6 =4.16 ft.
Arch length = (105 x 3.14 x 4.16)/180 = 7.61
Quantity of materials in arch = 1 x 7.61 = 7.61 cft.
HOW TO CALCULATE SHUTTERING AREA FOR
CONSTRUCTION
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Shuttering or formwork is a temporary, rigid structure in which the cast in situ concrete is
poured for casting the members to required shape. Different formworks are used for different
shape members.
In this article, we will discuss how to calculate the shuttering area before construction.
Before calculating the shattering area first, we need to know how to calculate the peripheral
length of any shape.
PERIPHERAL LENGTH/PERIMETER:
We know that perimeter is the distance around a 2D (two dimensional) shape.
For example, square has four sides. Let ‘s’ be the length of one side, then
∴ The peripheral length = s+s+s+s = 4s
Rectangle has four sides also but the length and breadth is different, let one side length is ‘l’
and breadth is ‘b’
∴ Peripheral length = l+b+l+b = 2l+2b
Now coming to the calculation of shuttering area.
Shttering area = Pheripheral length * Depth
Let me give you an example
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Pheripheral length = (2 * 1) + (2*0.8) = 2 +1.6 =3.6
∴ Total shuttering area = 3.6 * 4 = 14.4 sq.m
HOW TO CALCULATE CEMENT BAGS IN 1
CUBIC METER
PROCEDURE TO CALCULATE CEMENT BAGS IN 1 CUBIC METER:
Let us consider the nominal mix is 1:2:4
Loss of cement is considered as 2%
Output of mix is considered as 67%
To achieve 1 cum output, we need 1/0.67 = 1.49 say 1.50 cum dry mix.
Now add the wastage of 2%, i.e (1.50 + 0.02) = 1.52 cum.
Volume of cement = (cement/cement+sand+aggregate) × Total material
=(1/1+2+4) × 1.52
=0.2171 cum
As we know, the density of cement is 1440 kg/cum and
Weight of 1 bag cement = 50 kg.
Therefore volume of 1 bag cement = 50/1440
=0.0347 cum.
∴ No. of cement bags required in 1 cubic meter = 0.2171/0.0347
= 6.25 bags.
Note: You can use the same formula for calculating cement for other nominal mixes.
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QUANTITY OF CEMENT, SAND, & AGGREGATES
FOR 1000 SQ FT SLAB
To calculate the quantity of cement, sand, and aggregates required for a flat slab first we need
to calculate the volume.
Area of flat slab = 1000 sq.ft =93 sq. m.
The minimum thickness provided for slab is 150mm .( According to IS 456)
150 mm = 0.15 metres
Hence Wet volume = Area of slab x Thickness of slab
Wet volume = 93 x 0.15 = 13.95 cu. m.
To calculate the quantities of materials we need dry volume
Dry volume = Wet volume x 1.54
Check why 1.54 is multiplied with wet volume to get dry volume.
∴ Dry volume = 13.95 x 1.54 = 21.48 cu.m (approximately).
Generally, M20 grade concrete is predominantly used for construction purposes.
M20 = 1: 1.5: 3 (Cement:Sand:Aggregates) = (a:b:c)
QUANTITY OF CEMENT:
Quantity of cement = Dry volume x (a/{a+b+c}
Quantity of cement = Dry volume x (1/{1+1.5+3}) for M20 grade concrete.
= 21.48 x (1/5.5}) = 3.90 cu.m = 3.90 cu.m
We need the quantity of cement in terms of bags.
So by multiplying the quantity of cement with the density of cement, we will the get quantity of
cement in terms of kilograms.
Unit weight or Density of cement = 1440 kg/cu.m.
Quantity of cement in kg(s) = 1440 x 3.90 = 5616 kg
We know that 1 cement bag = 50 kgs
∴ No. of cement bags required = 5616/50 kg = 112.32 bags =112 bags.
QUANTITY OF SAND:
Quantity of sand = Dry volume x (b/{a+b+c}
∴ Quantity of sand = Dry volume x (1.5/{1+1.5+3}) for M20 grade concrete.
= 21.48 x (1.5/5.5}) = 5.85 cu.m
QUANTITY OF AGGREGATES:
Quantity of aggregates = Dry volume x (c/{a+b+c}
∴ Quantity of aggregates = Dry volume x (3/{1+1.5+3}) for M20 grade concrete.
= 21.48 x (3/5.5}) = 11.71 cu.m
SUMMARY:
Cement = 112 bags.
Sand = 5.85 cu.m
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Aggregates = 11.71 cu.m
Note: ConsiderYield of concrete as 67% &
Wastages of materials = 2%
You can use the same formula for different mix proportions such as 1:2:4 etc.
Here, we have calculated in cubic meter unit but you can calculate in cubic feet unit.
HOW TO CALCULATE VOLUME OF CONCRETE
FOR STAIRCASE:
Staircase is one of the essential parts of a building. It helps people to access different floors in a
building. In this article, I will explain how to estimate concrete volume and quantity of cement,
sand, aggregates for a staircase. Before starting the estimation, we need to know different
components of a staircase which I will use in this calculation.
COMPONENTS OF STAIRCASE:
STEPS:
A portion of stairway comprising the tread and riser which permits ascent and descent from
one floor to another.
TREAD:
The horizontal upper part of a step on which foot is placed in ascending or descending stairway.
RISER:
The vertical portion of a step providing support to the tread.
FLIGHT:
A series of steps without any platform, break or landing in their direction.
LANDING:
A platform or resting place provided between two flights.
Now coming to the calculation of concrete volume for the staircase.
Let’s take an example:
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The height of one floor = 12 feet.
Height to be acquired by one flight = 12/2 = 6 feet.
Risers = 6″ = 0.5 feet.
Number of risers = Height of flight / Riser = 6/0.5 = 12
Tread = 10″ = 0.8 feet.
Number of treads = (Numbers of risers -1) = 12 – 1
Thickness of waist slab = 6″ = 0.5 feet
Length of step = 5 feet
VOLUME OF CONCRETE FOR STEPS:
Volume of one step = 1/2 x riser x tread x length of step
= 1/2 x 0.5 x 0.8 x 5 = 1.03 = 1 cubic feet.
As we have 11 number of steps in a flight the volume of steps for first flight = 11 x 1 = 11 cubic
feet.
CONCRETE VOLUME FOR WAIST SLAB:
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To calculate the volume of concrete for waist slab we need to know the inclined length of the
waist slab.
Horizontal length of waist slab = Tread x Number of steps
=0.8333′ x 11 = 9.2 feet.
The height of the top of the landing from floor = Number of riser x Height of riser
= 12 x 0.5 = 6 feet.
The volume of concrete for waist slab = Inclined length of waist slab x Width of waist slab x
Thickness of waist slab
= 11′ x 5′ x 0.5′
= 27.5 cubic feet
∴ Volume of concrete for first flight = Volume of waist slab + Volume of steps
= 27.5+11 = 38.5 cubic feet
VOLUME OF CONCRETE FOR LANDING OF STAIRCASE:
Length of landing = 10.5 feet
Width of landing = 5 feet
Thickness of landing = 0.5 feet
∴ Concrete volume for landing = 10.5′ x 5′ x 0.5′ = 26 cubic feet.
CONCRETE VOLUME FOR 2ND FLIGHT OF THE STAIRCASE:
As the 1st light and 2nd flight are same in our staircase so the volume of concrete will be same.
Concrete volume for 2nd flight of the staircase = 38.5 cubic feet.
∴ Total volume of concrete for staircase = Volume of first flight + Volume of second flight +
Volume of landing
= 38.5 + 38.5 + 26
= 103 cubic feet.
Well, this is the wet volume of concrete. To convert wet volume into dry volume we need to
multiply with 1.54
∴ Dry volume of concrete = 103 x 1.54 = 159 cubic feet.
QUANTITY OF MATERIALS FOR STAIRCASE:
We will calculate for 1:2:4 Concrete mix.
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1. Volume of cement = 1/7 x Dry volume = 1/7 x 159 = 22.66 cubic feet.
∴ Number of Cement bags = volume of cement / Volume of cement bag = 22.66 / 1.25 = 18
No’s of bag. (The volume of one bag cement of 50 kg = 1.25 cubic feet)
2. Volume of Sand = 2/7 x Dry volume = 2/7 x 159 = 45 cubic feet.
3. Volume of Aggregate = 4/7 x Dry volume = 4/7 x 159 = 91 cubic feet.
Note: Here I have used cubic feet unit and 1:2:4 mix ratio, you can use cubic meter unit and
any other mix ratio of concrete.
WHAT IS 1.54 IN CONCRETE CALCULATION?
In concrete calculation, we always multiply Wet volume with 1.54 to get dry volume. But do you
know what is 1.54 or where this 1.54 came from? If You don’t know, no problem. In this article,
I will explain what is 1.54 while calculating quantity of cement, sand, aggregates for concrete.
let us take a concrete cube.
The length of the concrete cube = 1 m
The width of the concrete cube = 1 m
The height of the concrete cube = 1 m
Volume of concrete cube = length x Width x Height = 1 x 1 x 1 = 1 m³ (Wet volume)
When we convert this we volume into dry volume, the volume is increased by 54% of wet
volume.
∴ Dry volume = Wet volume + 54% of Wet volume
= 1 + (54/100) x 1 =1 + 0.54 = 1.54
To convert wet volume of 1 m³ concrete into dry volume = 1.54
To convert wet volume of “n” m³ concrete into dry volume = 1.54 x n
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Where n = Wet volume of concrete.
Example:
The length of the concrete cube = 4 m
The width of the concrete cube = 3 m
The height of the concrete cube = 2 m
Wet volume = 4 x 3 x 2 = 24 m³
∴ Dry volume = ( Wet volume + 54% of wet volume)
= 24 + {(54/100) x 24}
= 36.96 m³
Note:
Always remember in concrete calculation, we get wet volume first, to convert wet volume into
dry volume, multiply wet volume with 1.54.
HOW TO CALCULATE RECTANGULAR WATER
TANK SIZE AND CAPACITY
For high rise building, the dimension of water tank along with drawings are provided from
architect office.
But for small residential building, we need to calculate by itself. In this article, we will discuss
how to calculate rectangular water tank size and capacity.
VOLUME OF WATER REQUIREMENT:
As per IS code, a person needs 135 litres water per day for daily use.
Drinking – 5 Litre
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Cooking – 5 litres
Bathing and Toilet – 85 litres
Washing clothes and Utensils – 30 litres
House Cleaning – 10 litres
CALCULATION OF TANK SIZE AND CAPACITY:
We will calculate for a typical family having 4 members.
Total water requirement = 135 x 4 = 540 litres
To calculate the size of water tank we must know any one of the following:
Length or width or depth of the tank.
From the formula of volume of water
1 m3 = 1000 litres
1 litre = 0.001 m3
We are requiring 540 litre water
∴ 540 litres = 0.54 m3
Let us assume the depth of water tank is 0.6 m.
∴ Area of tank = 0.54/0.6 = 0.9 m2
L x B = 0.9 m2
Now if you know the length or breadth you can put the value on the above formula.
otherwise, take the length as 2 times of B.
∴ L = 2B
2B x B = 0.9 m2
B2 = 0.45
B = 0.67
∴ L = 2 x 0.67 = 1.34 m
So For 540 litre water tank size
Length (L) = 1.34 m
Breatdh (B) = 0.67 m
Depth (D) = 0.6 m
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SEPTIC TANK SHAPE, SIZE & DIMENSIONS
WITH TABLE
SEPTIC TANK SHAPE, SIZE & DIMENSIONS:
Septic tank is a devise which deals with the sewage from water closets. In other words, it is a
watertight single-storeyed, underground tank in which sewage is retained sufficiently long to
permit sedimentation of suspended solids and practical digestion of settled sludge by anaerobic
bacterial action.
SHAPE OF SEPTIC TANK:
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The simplest form of a septic form is a single compartment, rectangular or cylindrical in shape.
The shape of septic tank influences the flow speed of wastewater and sludge accumulation.
The dimension of the septic tank should not be too deeper too shallow. Because it can cause
short-circuiting of the inlet and outlet flow.
Septic tank having a greater surface area with sufficient depth should always be preferred.
Rectangular shaped single compartment tank (with length three times of its width) is more
favorable.
In some cases, cylindrical shape with suitable size is also sound to be a better choice.
SEPTIC TANK SIZES, DIMENSIONS & WEIGHTS:
SEPTIC TANK
SIZE
DIMENSIONS WEIGHT
(LBS)
ANCHOR WEIGHT
(LBS)
SOIL COVER
(IN)
5000 gal 204″L x 96″W
x93″H
41,400 30,850 24
3000 gal 165″L x 92″W x
76″H
20,300 23,320 23
2600 gal 147″L x 90″W x
73″H
18,100 20,625 24
2000 gal 162″L x 78″W x
64″H
16,100 15,675 19
1600 gal 145″L x 78″W x
61″H
14,000 11,270 16
1200 gal 111″L x 78″W x
61″H
11,400 9,532 17
1000 gal
Low Profile
120″L x 67″W x
57″H
9,500 8,705 17
1000 gal
Heavy Duty
96″L x 78″W x
61″H
9,200 8,945 18
800 gal 96″L x 67″W x
57″H
8,000 6,560 16
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600 gal 78″L x 56″W x
60″H
6,600 3,810 14
1600/1400 gal 174″L x 90″W x
73″H
23,000 22,410 22
1250/750 gal 162″L x 78″W x
64″H
16,400 15,725 19
1000/600 gal 145″L x 78″W x
61″H
14,700 12,705 17
DESIGN CRITERIA OF SEPTIC TANK
SEPTIC TANK:
Septic tank is a tank where sewage is kept a long time for sedimentation of suspended solid by
anaerobic microorganism activity.
Septic Tank Design
Basically, the tank is rectangular in shape consisting of rooftop with two chambers, isolated
from each other by a baffle wall. The first chamber is called grit chamber in which the sewage
enters first and the rest one is called anaerobic chamber.
Inlet and outlet pipe should be fitted in such a manner that while entering or existing there
should not be any unsettled influence in the sewage of anaerobic chamber. Sand, grit etc is
settled down in the grit chamber before the sewage is directed to the anaerobic chamber. In
the anaerobic chamber, natural solids settle at the base of the tank where anaerobic bacteria
follows up on it and changes over complex unsteady mixes to more straightforward stable
mixes.
SEPTIC TANK DESIGN:
The following measure should be kept in view to design a septic tank:
1. The floor zone of the git chamber must be adequate to decrease the speed of steam and to
allow sedimentation.
2. The capacity of a septic tank should be sufficient to give a detainment period fluctuating
from 12 hours to 3 days, 24 hours time frame is normally viewed as satisfactory.
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3. The depth beneath segment divider opening should be adequate to allow aggregation for the
predetermined period. A minimum area of 0.07 m2 for each client in grit chamber and
minimum volumetric substance of the grit chamber of 0.02 m3 for every client is required.
4. The minimum width and depth of a septic tank should be 0.75 m and 1 meter underneath
water level. The length should be 2 to 4 times of the width. The minimum capacity of a septic
tank is granted 1 m3.
5. Every septic tank should be furnished with a ventilating channel minimum diameter of 5 cm.
HOW TO CALCULATE VOLUME OF CONCRETE,
SHUTTERING AREA & BITUMEN PAINT AREA
FOR PLAIN FOOTING
In this article I will discuss how to calculate the volume of concrete, shuttering area and
bitumen paint area for plain footing (Square footing & Rectangular footing).
A. SQUARE FOOTING:
Given,
Length of footing = 0.5 m
Breadth of footing = 0.5 m
Depth of footing = 0.25 m
Size of column = 0.2 x 0.1
1. Volume of concrete = Area of sq. footing x Depth of sq footing
Area of sq. footing = L x B = 0.5 x 0.5 = 0.25 m²
Volume of concrete = 0.25 x 0.25 = 0.0625 m³.
2. Shuttering area = 2 (L + B) x D
= 2 (0.5+0.5) x 0.25
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= 0.5m²
3. Bitumen paint area = Shuttering area + (Top area of footing – column area)
= 0.5 + [(0.5 x0.5) -(0.2 x 0.1)]
=0.5 + [0.25 – 0.2)]
= 0.73 m².
2. RECTANGULAR FOOTING:
Given,
Length of footing = 1 m
Breadth of footing = 0.7 m
Depth of footing = 0.25 m
Size of column = 0.4 x 0.3
1. Volume of concrete = Area of sq. footing x Depth of sq footing
Area of sq. footing = L x B = 1 x 0.7 = 0.7 m²
Volume of concrete = 0.7 x 0.25 = 0.175 m³.
2. Shuttering area = 2 (L + B) x D
= 2 (1+0.7) x 0.25
= 0.85m²
3. Bitumen paint area = Shuttering area + (Top area of footing – column area)
= 0.85 + [(1 x0.7) -(0.4 x 0.3)]
=0.85 + [0.7 – 0.12)]
= 1.43 m².
HOW TO CALCULATE CEMENT, SAND
QUANTITY FOR PLASTERING?
Following points should be remembered while calculating the quantity of cement, sand for
plastering work.
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1. For wall plastering, Cement : Sand = 1 : 6
2. For ceiling plastering, Cement : Sand = 1 : 4
3. Thickness of plaster should be in between 12-15 mm. If an additional coat is required then do
not do it at one go.
4. Use good quality of cement & Sand.
5. Use measuring box (not head pan) for site mix.
We will calculate cement and sand for 100 m2 plastering area in 1:6 ratio and thickness of 12
mm.
Cement Mortar Required:
Plastering thickness = 12 mm
= 12/1000 = 0.012m
Volume of cement mortar required = ( Plastering Area x thickness )
= 100 m2 x 0.012m = 1.2 m3
(This is wet volume of cement mortar (after mixing water) but we need dry volume. To get dry
volume consider 35% bulking of sand and 20% wastages
= 1.2 m3 x (1+0.2+0.35) (Rather than 35% sand bulkage and 20% wastage you can add 1.54 as
constant)
= 1.86 m3
Cement : Sand = 1 : 6
Sum of ratio =( 1 + 6) = 7
∴ Cement required
= 1.86 x 1/7
= 0.265 m3
= 0.265/0.0347 ( 0.0347 m3 = 1 bag = 50 kg cement)
= 7.66 bags (≈ 8 Bags)
∴ Sand required
= 1.86 x 6/7
= 1.59 m3
Here we have calculated in Sq.m but you can also calculate it in Sq.ft.
HOW TO CALCULATE QUANTITY OF PAINT
FOR BUILDING:
Painting is one of the most essential steps to be done after construction of any building/house.
Painting is done to protect the surface of the walls as well as to increase appearance.
In this article, I will discuss how to calculate the quantity of paint required in a building.
Before starting the calculation let me tell you one important thing that quantity of paint is
calculated in gallon.
There are two types of gallons
US gallon and Uk gallon.
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1 US gallon = 3.785 litres
1 Uk gallon = 4.546 litres.
In this calculation we will use US gallon.
Let the length of the wall = 15 feet
The height of the wall = 12 feet.
Area of the wall 15 x 12 = 180 sft.
THUMB RULE FOR PAINT CALCULATION:
Generally, 1 gallon of paint can cover up to 350 sft area of wet wall and
1 gallon of paint can cover up to 200 sft area of dry wall.
PAINT QUANTITY OF WET WALL:
Area of wet wall =180 sft
Paint covered area = 300 sft
Quantity of paint = 180/350 = 0.514 litre.
Let the price of 1 gallon paint = Rs 1200.
Price of 0.514 gallon paint = 0.514 x 1200 = 617 Rs.
PAINT QUANTITY OF DRY WALL:
Area of dry wall = 180 sft.
Pain covered area = 200
Quantity of paint = 180/200 =0.9 gallon.
Price of 0.9 gallon paint = 0.9 x 1200 = 1080 Rs.
Note:
1. If the wall has any openings, subtract the area of openings from total area & then calculate
paint quantity.
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HOW TO CALCULATE SHUTTERING OILAND
ITS PRICE
Shuttering oil is very useful material required for every construction projects. So it is very
important to know the shuttering oil quantity. In this article, I will discuss how to calculate
shuttering oil and its price.
Before starting the calculation let me tell you first what is shuttering oil and why we use it in
shuttering/formwork.
WHAT IS SHUTTERING OIL?
Shuttering oil are high quality mineral oil which is used on the shuttering plates/mould for easy
removal of shuttering.
WHY WE USE SHUTTERING OIL IN FORMWORK?
The main purposes of using shuttering oil are as follows:
1. Shuttering oil works as a releasing agent between shuttering plates and concrete. It helps
easy removal of shuttering at the time of deshuttering.
2. It gives a good and better finish after deshuttering.
3. It keeps the shuttering plates and mould in good condition and ensures repetitive use in
more projects.
HOW TO CALCULATE SHUTTERING OIL & ITS PRICE:
Let us calculate the quantity of shuttering oil for the above slab.
Length of slab = 12 m
Breadth of slab = 10 m
Area of slab = L x B = 12x 10 = 120 m²
There are two types of shuttering plates used in construction.
1. WOOD SHUTTERING:
Generally, 1 liter shuttering oil covers upto 30 to 40 m² area in wood shuttering.
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The quantity of shuttering oil = Total area/1 liter covering area
= 120/30 = 4 litre
Price: Let the price of 1 liter shuttering oil = Rs. 250.
The price of 4 liter shuttering oil = 250 x 4 = Rs. 1000.
2. STEEL SHUTTERING:
Generally, 1 liter shuttering oil covers upto 60 to 70 m² area in steel shuttering.
The quantity of shuttering oil = Total area/1 liter covering area
= 120/60 = 2 litre
Price: Let the price of 1 liter shuttering oil is Rs. 250.
The price of 2 liter shuttering oil = 250 x 2 = Rs. 500.
HOW TO CALCULATE CONCRETE VOLUME
FOR RETAINING WALL:
Retaining wall is a masonry wall constructed to resist the pressure of liquid, earth filling, sand or
other granular material filled behind it.
In this article, I will discuss how to calculate the concrete volume for retaining wall. Let’s get
started.
EXAMPLE 1:
To calculate the volume of retaining wall we need to calculate the volume of retaining wall.
Here I have divided the retaining wall into two parts, part A is the base slab and part B is the
stem of retaining wall.
So Volume of retaining wall = Volume of base slab + Volume of stem.
Volume of base slab = l x b x h = 10 x 3 x 0.2 = 6 m³
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The stem is a trapezoid.
So Volume of stem = [{(a + b)/2} x h] x l
= [{(0.5 + 0.2)/2} x 3] x 10
= 21 m³
The total volume of retaining wall = 6 + 21 = 27 m³
So the volume of concrete for the retaining wall = 27 m³
Let’s take another example:
EXAMPLE 2:
Here I have divided the retaining wall into three parts, part A is the base slab, part B is the stem
and part C is the counterfort of the retaining wall.
The volume of retaining wall = Volume of base slab + Volume of stem + Volume of counterfort
= Volume of A + Volume of B + Volume of C
Volume of A = l x b x h = 12 x 2.5 x 0.2 = 6 m³
Part B is a trapezooid.
So Volume of B = [{(a + b)/2} x h] x l = [{(0.2 + 0.3)/2} x 3] x 12
= 9 m³
As part C is also a trapezoid
So
Volume of C = [{(a + b)/2} x h] x l = [{(0.5 + 2)/2} x 3] x 0.2 = 0.75 m³
In the above retaining wall there is 2 counterfort so
Volume of C = 0.75 x 2 = 1.5 m³
The total volume of retaining wall = 6 + 9 + 1.5 = 16.5 m³.
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HOW TO CALCULATE NUMBER OF TILES IN A
ROOM:
Calculation of tiles needed for floors and walls is so simple and easy. in this post, I will discuss
how to calculate no. of tiles required in a room. So let’s start.
STEP 1- CALCULATE AREA OF THE FLOOR:
let the length of the floor = 14 feet.
Breadth of the floor = 12 feet.
∴ Area of floor = length of floor x breadth of floor = 14 x 12 = 168 sft.
STEP 2 – CALCULATE AREA OF 1 TILE:
There are different tile sizes such as 20cmx20cm, 30cmx30cm, 45×45, 60cmx60cm etc. In this
calculattion we will use 60×60 cm tiles.
Length of 1 tile = 60 cm
Breadth of 1 tile = 60 cm.
∴ Area of 1 tile = 60 x 60 = 3600 cm² = 3.6 sft.
STEP 3 – DIVIDE FLOOR AREA BY AREA OF 1 TILE:
∴ No. of tiles required = Area of floor/ area of 1 tile = 168/3.6 = 46.6 ≈ 47.
∴ 47 tiles are required for the above floor.
Note:
Consider 5% wastages.
Similarly, you can also calculate tiles needed for walls.
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HOW TO CALCULATE LAND AREA OR PLOT
AREA:
Sometimes we may need to know the area of any land or plot for various reasons such as
buying, selling of land, or constructing house/building etc. In this article, I will explain how to
calculate land are or plot area for a site.
Area Formula For Different Shapes:
But for complex shaped land you cannot easily calculate the area. In that case, we use HERON’s
Formula which is given below:
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Where S = Perimeter of the triangle
S = (a + b + c)/2
a = Distance of AB
b = Distance of BC
c = Distance of AC
Let’s take an example,
First of all, divide the land area into minimum possible no. of triangle. Then measure all the
required distance (like AB, AC, AE etc) by using a tape or chain.
1. FOR △ ACD:
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AC = 10 feet.
CD = 12 feet.
AD = 14 feet.
S = (a + b + c)/2 = (10 + 12 + 14)/2 = 18 feet.
2. FOR △AED:
AD = 14 feet.
AE = 14feet.
DE = 12 feet.
S = (a + b + c)/2 = (14+14+12)/2 = 20 feet.
3. FOR △AEB:
AB = 16 feet.
BE = 12 feet.
AE = 12 feet.
S = (a + b + c)/2 = (16 + 12 + 12)/2 = 20 feet.
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Total Area Of Land = 58.78 + 75.89 + 71.55 = 206.22 ft²
NOTE: This method does not give appropriate result for curve shaped area, for curve shaped
area we need to use difinite integral method.
CENTER LINE METHOD OF ESTIMATION:
There are three different methods of estimation.
1. Center line method.
2. Long and short wall method.
3. Crossing method.
In this article, I will discuss center line method briefly for the estimation of materials.
WHAT IS CENTER LINE METHOD:
In this method of estimation, the total center line length of walls in a building is first calculated,
then the center line length is multiplied with the breadth and depth of respective item to get
the total quantity at a time.
The center line length for different sections of walls in a building shall be worked out
separately. For verandah walls or partition walls joining the main walls, the center line length
shall be reduced by half of the breadth of the layer of main wall that joins with the partition or
verandah wall at the same level. The number of such joints is studied first to obtain the center
line length.
By using this method estimation can be finished more quickly. This method is as accurate as
other methods (except unsymmetrical wall). This method is suitably used for estimating
circular, rectangular, hexagonal, octagonal etc shaped building.
Let us take an example:
FOR ONE ROOM BUILDING:
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First we need to calculate total center line length of the building.
Total center line length = 2 x 5.3 + 2 x 4.3 = 19.2 m.
1. Earthwork in excavation = Total center line length x breadth x depth
= 19.2 x 0.9 x (0.3+0.3+0.3)
= 19.2 x 0.9 x 0.9
= 15.52 cu.m
2. Concrete in foundation = 19.2 x 0.9 x 0.3 = 5.18 cu.m
3. a) Brickwork in foundation for 1st footing = 19.2 x 0.6 x 0.3 cu.m
b) Brickwork in foundation for 2nd footing = 19.2 x 0.5 x 0.3 = 2.88 cu.m
4. Brickwork in superstructure = 19.2 x 3.5 x 0.3 = 20.16 cu.m
FOR TWO ROOM BUILDING:
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Total center line length = 2 x (5.3+5.3) + 3 x 4.3 = 34.1 m.
1. Earthwork in excavation = Total center line length x breadth x depth
= 34.1 x 0.9 x (0.3+0.3+0.3)
= 34.1 x 0.9 x 0.9
= 27.62 cu.m
2. Concrete in foundation = 34.1 x 0.9 x 0.3 = 9.20 cu.m
3. a) Brickwork in foundation for 1st footing = 34.1 x 0.6 x 0.3 = 6.13 cu.m
b) Brickwork in foundation for 2nd footing = 34.1 x 0.5 x 0.3 = 5.11 cu.m
4. Brickwork in superstructure = 34.1 x 3.5 x 0.3 = 35.8 cu.m
Thus you can estimate quantity of different items such as
Quantity of D.P.C = Total Centre line length x Breadth of foundation x Thickness of D.P.C
Quantity of plinth beam = Total Centre line length x Breadth of the beam x Depth of beam.
Quantity of wall plaster for 2 sides = Total centre line length x Height of wall x Thickness of
plaster.
Quantity of Paint for 2 sides of wall = Total centre line length x Height of wall x 2 = Area of
paint in sq.ft
ONE WAY SLAB DESIGN – HOW TO DESIGN ONE
WAY SLAB
In this article, I will discuss how to design One way slab with example.
WHAT IS ONE WAY SLAB?
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When a slab is supported on all four sides and the ratio of long span to short span is equal or
greater than two, it will be considered as one way slab. The load on the slab is carried by
the short span in one direction. However main reinforcement bar and distribution bar in
transverse direction.
Longer span (l)/Shorter span (b) ≥ 2
ACI CODE SPECIFICATIONS FOR ONE WAY
SLAB DESIGN:
1. MINIMUM SLAB THICKNESS:
To control deflection, ACI Code 9.5.2.1 specifies minimum thickness values for one-way solid
slabs.
2. SPAN:
According to ACI code 8.7.1 If the slab rests freely on its supports, the span length may be taken
as equal to the clear span plus the depth of the slab but need not exceed the distance between
centers of supports.
3. BAR SPACING:
The lateral spacing of the flexural bars should not exceed 3 times the thickness h or 18 inch
according to ACI code 7.6.5 The lateral spacing of temperature and shrinkage reinforcement
should not be placed farther apart than 5 times the slab thickness or 18 inch according to ACI
code 7.12.2
4. MAXIMUM REINFORCEMENT RATIO:
Reinforcement ratio is the ratio of reinforcement area to gross concrete area based on total
depth of slab. One-way solid slabs are designed as rectangular sections subjected to shear and
moment. Thus, the maximum reinforcement ratio corresponds to a net tensile strain in the
reinforcement, €t of 0.004
5. MINIMUM REINFORCEMENT RATIO:
A) FOR TEMPERATURE AND SHRINKAGE REINFORCEMENT :
According to ACI Code 7.12.2.1
Slabs with Grade 40 or 50 deformed bars –> 0.0020
Slabs with Grade 60 deformed bars –> 0.0018
Slabs where reinforcement with yield strength Exceeding 60000 psi- ->( 0.0018 x 60000/fy)
B) FOR FLEXURAL REINFORCEMENT :
According to ACI Code 10.5.4, the minimum flexural reinforcement is not to be less than the
shrinkage reinforcement, or 0.0018
EXAMPLE PROBLEM:
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A reinforced concrete slab is built integrally with its supports and consists of equal span of 15 ft.
The service live load is 100 psf and 4000 psi concrete is specified for use with steel with a yield
stress equal to 60000 psi. Design the slab following the provisions of the ACI code.
THICKNESS ESTIMATION:
For being both ends continuous minimum slab thickness = L/28 =(15 x 120)/28= 6.43 in.
Let a trial thickness of 6.50 in.
LOAD CALCULATION:
Consider only a 1 ft width of beam.
Dead load = 150 x (6.50/12)) = 81 psf
Live load = 100 psf
Factored DL and LL ={81+1.2+(100 x 1.6)} =257 psf
DETERMINE MAXIMUM MOMENTS:
Factored moments at critical sections by ACI code :
At interior support : -M=1/9 x 0.257 x 152 = 6.43 k-ft
At midspan : +M=1/14 x 0.257 x 152 = 4.13 k-ft
At exterior support : -M=1/24 x 0.257 x 152 = 2.41 k-ft
Mmax = 6.43 k-ft
=0.85 x 0.85 x 4/60 x 0.003/(0.003+0.004)
= 0.021
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Now,
= 2.64 in
CHECK FOR AVAILABILITY OF THICKNESS:
As ‘d’ is less than the effective depth of (6.50-1.00) = 5.50 in, the thickness of 6.50 in
can be adopted.
REINFORCEMENT CALCULATION:
Let, a = 1 inch
At interior support:
Checking the assumed depth of a by
Similarly at Midspan:
As = (4.13 x 12)/(0.90 x 60 x 5.29) = 0.17 in²
At Exterior support:
As = (2.41 x 12)/(0.90 x 60 x 5.29) = 0.10 in²
MINIMUM REINFORCEMENT:
As = 0.0018 x 12 x 6.50 = 0.14 in²
So we have to provide this amount of reinforcement where As is less than 0.14 in².
SHRINKAGE REINFORCEMENT:
Minimum reinforcement for shrinkage and temperature is
As = 0.0018 x 12 x 6.50 = 0.14 in²
FINAL DESIGN:
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LAYOUT OF ONE WAY SLAB:
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DESIGN OF COLUMNS AS PER ACI:
1. Maximum and Minimum Reinforcement Ratio:
The minimum reinforcement ratio of 1 % is to be used in tied or spirally reinforced columns.
This minimum reinforcement is needed to safeguard against any bending, reduce the effect of
shrinkage and creep and enhance ductility of columns.
2. Minimum Number of Reinforcing Bars:
Minimum four bars within rectangular or circular sections; or one bar in each corner of the
cross section for other shapes and a minimum of six bars in spirally reinforced columns should
be used.
3. Clear Distance between Reinforcing Bars:
For tied or spirally reinforced columns, clear distance between bars should not be less than the
larger of 150 times bar diameter or 4 cm.
4. Concrete Protection Cover:
The clear concrete cover should not be less than 4 cm for columns not exposed to weather or in
contact with ground. It is essential for protecting the reinforcement from corrosion or fire
hazards.
5. Minimum Cross-Sectional Dimensions:
For practical considerations, column dimensions can be taken as multiples of 5 cm.
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6. Lateral Reinforcement:
Ties are effective in restraining the longitudinal bars from buckling out through the surface of
the column, holding the reinforcement cage together during the construction process, confining
the concrete core and when columns are subjected to horizontal forces, they serve as shear
reinforcement. Spirals, on the other hand, serve in addition to these benefits in compensating
for the strength loss due to spalling of the outside concrete shell at ultimate column strength.
7. Ties:
For longitudinal bars, 32 mm or smaller, lateral ties 10 mm in diameter should be used. In our
country and in some neighboring countries, ties of 8 mm dia are used for column construction
CALCULATION OF EARTH PRESSURE:
The thrust due to the back filling, which may be assumed to be earth, is generally calculated by
Rankine’s theory. The theory is based on the assumption that the backing material or earth
consists of cohesionless granular particles. The formulae derived from this theory under
different conditions of backfilling are given below:
Case 1: Walls with earth levelled with the top of the wall:
a) Horizontal pressure per sq.m (ph) at a depth of (h) meter below the levelled top is given by
the following formula:
Where
w = Weight of filling in kg/m3
ϕ = Angle of repose of the soil.
b) Total horizontal pressure (P) at a depth of (h) meter per meter length of the wall is given by
the following formula:
Acting at h/3 meter from the base.
Case 2: In case of submerged retaining wall or wall retaining earth filled at slope of a° to the
horizontal, the formula giving lateral earth pressure (ph) is given by:
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Acting parallel to the surcharge slope of the filling.
Total pressure (P) at depth h meter per meter length of the wall is given by the formula:
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How to calculate quantity of mortar and its materials
Below is the step by step process of calculating quantity of mortar required
for cementing.
 Area of the surface multiply with the thickness gives the quantity of mortar for
uniform thickness.
 This quantity is increased by 30% for filling the joints and to make up uniform surface
of wall. It will give wet mixed mortar.
 This mortar quantity is further increased by 25% to get the dry volume
of the ingredients.
 Quantity of each material of the mortar may be found by dividing the dry
volume of mortar by the sum of numerals of the proportions and
multiplying the answer with the individual numeral.
For example
Materials for 12 mm or half inch thick plastering in wall for 100 square
meter
 First of all, we have to multiply 100 square meter surface with 12 mm.
 100 square meter x 0.012 m = 1.2 cubic meter. (12 mm can also be written as 0.012)
 1.2 cubic meter is wet mixed mortar for uniform thickness.
 Add 30% in this value to fill up joints, uneven surfaces, etc., the quantity of mortar
comes out 1.2 + 0.36 = 1.56 cubic meter.
 Increasing by 25% the total dry volume will be 1.2+0.36+0.39 = 1.95 cubic meter or
2 cubic meter.
 For cement sand mortar, cement = dry volume / ( sum of ratios) x numeral of
cement.
 For 1:4 cement sand mortar, cement will be 2/5 x 1 = 0.4 cubic meter.
 For 1:4 cement sand mortar, sand will be 2/5 x 4 = 1.6 cubic meter.
 In this way you can calculate the dry volume of any ratio of mortar ingredients.
Measurement of Plinth Area and Carpet Area of a
Building
Plinth area and carpet area of a building is measured for estimation and calculation of building
cost. It is also a measure of usable space of building.
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Plinth area is the covered built-up area measured at the floor level of any storey or at the floor
level of the basement. Plinth area is also called as built-up area and is the entire area occupied
by the building including internal and external walls. Plinth area is generally 10-20% more than
carpet area.
Fig.1: Plinth Area of a Room in Building
Carpet area the covered area of the usable spaces of rooms at any floor. It is measured
between walls to walls within the building and is the sum of the actual areas of the rooms
where you can carpet.
Fig.1: Carpet Area of a Room in Building
Measurement of Plinth Area and Carpet Area of a Building
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For measurement, the lengths and widths should be measured nearest to 0.01m and areas
should be rounded to 0.01 m2. In Case of feet system, length should be measured to nearest 1
inch.
During the measurement, following categories are measured separately:
Basement
Floor without cladding (stilled floor)
Floors including top floor which may be partly covered
Garage
Mezzanine floor
Measurement of Plinth Area
Following areas are included during measurement of plinth area:
1. Area of the wall at the floor level, excluding plinth offsets. If there are any common
walls between two buildings, half of the area of such walls shall be considered in the
plinth area. When building consists of columns projecting beyond the cladding, the
plinth area is measured upto the external face of the cladding (in case of corrugated
sheet, cladding outer edge of the corrugation is considered).
2. Areas of the internal shaft for sanitary installations and garbage chute, electrical,
telecom and firefighting services provided these do not exceed 2 m2 in area.
3. Vertical duct for air conditioning and lift well including landing.
4. Staircase room or head room other than terrace level
5. Machine room
6. Porch
7. Open projections of veranda, balconies and parapets, if the area is protected by
projections, full area is included in plinth area, if the area is un-protected by projections,
50% of the area is included.
8. Recess by cantilevering beyond external walls, bay window is the best example. If the
recess height is up to 1.0 meter, 25% of such area shall be included. If the recess height
is 1.0 to 2.0 meters, 50% of such area shall be included. If the recess height is above 2.0
meters, 100% of such area shall be included.
The following is not to be included in the calculation of plinth area:
1. Additional floor for seating in assembly buildings, theatres, auditoriums
2. Cantilevered porch
3. Balcony
4. Area of loft
5. Internal sanitary shaft and garbage chute, provided these are more than 2 m2 in area
6. Area of architectural band, cornice, etc.
7. Area of vertical sun breaker or box louver projecting out and other architectural
features such as slab projection for keeping flower pots
8. Open platform
9. Terrace at first floor
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10. Spiral staircase including landing
11. Towers, turrets, domes projecting above the terrace level at terrace.
Wall Area in Plinth Area Calculation
Wall area is also included in plinth area calculation. Wall area is the area on plan occupied by
walls on any particular floor. It includes the thickness of any finishing or dado tiles if the height
of such wall is more than 1m from floor finish.
Following should be included in wall area of the building:
1. Area on plan occupied by doors and other openings
2. Intermediate pillars, supports and other such obstructions within the plinth area
irrespective of their locations
3. Pilasters along wall if exceeding 300 cm2 in area
4. Flues within the wall
5. Built-in cupboards, wardrobes, shelves appearing within a height of 2.2m from floor
6. Fire place projecting beyond the face of wall in living or bed room
The following is not included in wall area:
1. Pilaster along wall not exceeding 300 cm2 in are
2. Platforms projecting beyond the face of the wall
Measurement of the Carpet Area of the Building
Carpet area is the plinth area less the area of the following portions of the building:
1. Wall area
2. Veranda
3. Corridor and passage
4. Entrance hall and porch
5. Staircase and stair cover
6. Lift shaft and machine room for lift
7. Bathroom and lavatory
8. Kitchen and pantry
9. Store
10. Canteen
11. Air conditioning duct and plant room
12. Shaft for sanitary piping
13. Stilted floor and garage
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  • 1. 1 | P a g e SAQIB IMRAN 0341-7549889 1 Assala mu alykum My Name is saqib imran and I am the student of b.tech (civil) in sarhad univeristy of science and technology peshawer. I have written this notes by different websites and some by self and prepare it for the student and also for engineer who work on field to get some knowledge from it. I hope you all students may like it. Remember me in your pray, allah bless me and all of you friends. If u have any confusion in this notes contact me on my gmail id: Saqibimran43@gmail.com or text me on 0341-7549889. Saqib imran.
  • 2. 2 | P a g e SAQIB IMRAN 0341-7549889 2 How to Calculate the Square Meters of a Room To calculate a rectangular room's area in square meters, multiply its length in meters by its width in meters. If the room is an odd shape, break the shape down into individual rectangles, calculate the area in square meters for each rectangle, and then add the areas of all the rectangles for the room's total area in square meters. Measure Length and Width To calculate the area of a room, you need to know its length and width. Since you want the result in square meters, both measurements should be taken in meters. Most measuring tapes have metric measurements along one side, so just make sure you read the right side of the tape and always write down the measurements to cut down on mistakes and to keep from having to remeasure if you forget. Converting Meters to Feet If you've already measured the room in feet, you don't have to remeasure. Instead, grab a calculator and make the conversion to meters by dividing the number of feet in each measurement by 3.2808. If your room measures 13 feet long on one side, after the conversion, you have 13 ÷ 3.2808 = 3.96 meters. Calculating the Area of a Room Now that you know the room's length and width in meters, you calculate its area using the formula length × width = area. If the room is 4 meters long and 3 meters wide, its area is 4 meters × 3 meters = 12 square meters. If the room is 6 meters long and 5 meters wide, its area is 6 meters × 5 meters = 30 square meters. When you multiply one measurement in meters by another measurement in meters, the result should always be labeled as square meters to avoid confusion. You can also write square meters as meters2, which is read as meters squared. Measuring Odd-Shaped Rooms The formula works if your room is a square or rectangle shape, but sometimes rooms are L- shaped, or maybe you want to measure the free floor space around the furniture that's already in the room. In that case, the easiest method is to break the room's shape into individual rectangles. Calculate the area of each rectangle in square meters and then add the areas to get the total area of the room in square meters. If you have an L-shaped room that you broke down into two rectangles – one measuring 2 meters by 5 meters and the other measuring 5 meters by 4 meters – the area of the first rectangle is 2 meters × 5 meters = 10 square meters, and the
  • 3. 3 | P a g e SAQIB IMRAN 0341-7549889 3 area of the second rectangle is 5 meters × 4 meters = 20 square meters. Add those together to get the total area of the room: 10 square meters + 20 square meters = 30 square meters.
  • 4. 4 | P a g e SAQIB IMRAN 0341-7549889 4 Calculating an Area in Square Meters Measure the length of the area you're measuring. Square meters are a unit for measuring area, or the size of a two-dimensional object such as a floor or a field. Use your measuring tool to measure one side of the object, from one corner to the other. Write down the result.  If the object is longer than 1 meter, remember to include both the meter and centimeter parts of the measurement. For instance, "2 meters 35 centimeters."  If you want to measure an object that isn't rectangular or square, read the Complex Shapes section instead. If you can't measure the entire length at once, do it in stages. Lay out the measuring tool, then put down a rock or other small object exactly at an easy to remember mark (like 1 meter or 25 centimeters). Pick up the tool and lay it down again, starting at the small object. Repeat until the entire length is covered, and add all your measurements together. Measure the width. Use the same tool to measure the width of the same area or object. The side you measure in this step should be angled close to 90º away from the length of the object you measured earlier, like two sides of a square next to each other. Write this number down as well.  Unless the object you're measuring is much smaller than 1 meter, you can round to the nearest centimeter when making your measurements. For instance, if the width is slightly past the 1 meter 8 centimeter mark, just use '"1m 8cm" as your measurement, without using decimals or millimeter measurements. Convert from centimeters to meters. Usually, the measurements won't divide evenly into meters. Instead, you'll have a measurement in both meters and centimeters, for example "2 meters 35 centimeters." Because 1 centimeter = 0.01 meters, you can convert a centimeter measurement into meters by moving the decimal point two digits to the left. Here are a couple examples:  35cm = 0.35m, so 2m 35cm = 2m + 0.35m = 2.35m  8cm = 0.08m, so 1m 8cm = 1.08m Multiply the length and width together. Once both measurements are converted into meters, multiply them together to get the measurement of the area in square meters. Use a calculator if necessary. For example:  2.35m x 1.08m = 2.538 square meters (m2). Round to a more convenient measurement. If you get a long decimal as an answer, for instance 2.538 square meters, you'll probably want to round it to a number with fewer digits, for instance 2.54 square meters. In fact, since you probably didn't measure correctly down to the tiniest fraction of a meter, the last digits probably aren't accurate anyway. In most cases, you
  • 5. 5 | P a g e SAQIB IMRAN 0341-7549889 5 can round to the nearest centimeter (0.01m). For a more accurate measurement, learn how to round to the significant digits. Whenever you multiply two numbers with the same units (for instance, meters), the answer is always in the form of that unit squared (m2, or square meters). Converting from Other Units Multiply square feet by 0.093. Measure the length and width in feet and multiply them together to get a result in square feet. Since 1 square foot = 0.093 square meters, multiply your result by 0.093 to get the answer in square meters instead. Square meters are bigger than square feet, so it will take fewer of them to cover the same area. For greater precision, multiply by 0.092903 instead. Multiply square yards by 0.84. If you have the measurement in square yards, multiply by 0.84 to get the measurement in square meters. For greater precision, multiply by 0.83613 instead. Multiply acres by 4050. One acre contains about 4050 square meters. If you want to be more precise, multiply by 4046.9 instead. Convert square miles to square kilometers instead. One square mile is much, much larger than a square meter, so typically it is converted into square kilometers instead. Multiply the square miles by 2.6 to find the area in square kilometers instead. (Or multiply by 2.59 instead to be more precise.) If you really want to convert to square meters, 1 square kilometer = 1,000,000 square meters. Convert square meters to units of area, not length. Square meters are a unit that measures area, or two-dimensional surfaces. It doesn't make any sense to compare them with units that measure length, or distance in one direction. You can convert between "square meters" and "square feet," but not between "square meters" and "feet." Don't use the calculations in this section to convert between units of length. That requires different numbers. Calculating Square Meters for a Complex Shape Break the shape up into pieces. If you are solving a math problem, draw or cut lines in the shape to divide it into simpler shapes, such as rectangles and triangles. If you are measuring a room or other physical object, sketch a diagram of the area first, then do the same thing. Take measurements of each section and write them on the diagram. Follow the instructions below to find the area of each section, then add the results together. Measure rectangle shaped pieces as you would normally. To find the area in square meters for rectangular sections, see the instructions for calculating an area in square meters. If you are measuring in a different unit, look at the section on other units. Measure right triangles similarly, then divide by two. A right triangle, which has a 90º angle just like the corners of a square, has an area easy to calculate. Measure the two sides next to that
  • 6. 6 | P a g e SAQIB IMRAN 0341-7549889 6 90º corner (the length and width), multiply them together, then divide by two to get the answer in square meters. This works because a right triangle is exactly the size of a rectangle cut in half. Basically, you found the area of a rectangle as usual, then divided by two to get the area of the triangle. Turn other triangles into right triangles, then measure them. Draw a line from any corner of a triangle to the opposite side, so that the line hits the opposite side at a 90º angle (picture the corner of a square). You've just divided the triangle into two pieces, each one a right triangle! See above for instructions on how to find the area of a right triangle; measure each of the two sub-triangles separately, and add them together. Calculate the area of a circle. The area of a circle is πr2, where r is the radius, or distance from the center of the circle to the rim, or perimeter. Measure this distance, multiply it by itself, then multiply the result by π on a calculator. If you don't have a calculator with a π function, use 3.14 instead (or 3.1416 if high precision is required).  If you're not sure where the center is, have a friend hold a tape measure and walk around the edge of the circle. Hold the other end of the tape measure and adjust your position until the measurement stays the same while your friend walks around the entire edge.  More complicated curved boundaries require more advanced math to calculate. If you are measuring a room for practical purposes, it might be easier to estimate the area by pretending the curved surfaces are a series of straight lines. How many square meters is 30 cm by 15 meters? 30 cm x 15 meters = 0.3 m x 15 m = 4.5 square meters. What is the difference between a square meter and metre squared? They're two ways of saying the same thing. The latter is the British way of saying it. How do I convert square meters to feet? If you mean square feet, there are 10.76 square feet in one square meter. How do I convert 20 meters in to square meters? If the length and width of the space are both 20 meters, 20 x 20 = 400 square meters. How do I calculate how many tiles I need in a square meter? Find the area of the tile by multiplying its length by its width. Then divide that area into one square meter. That tells you how many tiles will fit into a square meter. For example, if a tile is a square 5 cm on a side, its area is 25 cm². A square meter contains 10,000 cm², so you'd divide 25 into 10,000 to get 400, the number of tiles you'd need to cover a square meter. How do I calculate cost per square meter? Divide total cost by the number of square meters.
  • 7. 7 | P a g e SAQIB IMRAN 0341-7549889 7 How many feet is in a lot that is 6 x 10 meters in dimension? If you're asking about square feet, you would multiply the two lengths and then multiply by 10.76 (the number of square feet in a square meter). How many square meters equal a square foot? There are 10.76 square feet in one square meter. That means there is 0.093 square meter in one square foot. How do I calculate the area of a triangle? Multiply the length of a base of the triangle by the length of the corresponding altitude and divide the product by two. How many times does 370mm by 3m fit into 45 square meters? Convert mm to m, multiply the two lengths together, then divide that into 45. Methods of Measurements and Units of Civil Construction Works The methods and units of measurements for civil construction works are mainly categorised for their nature, shape and size and for making payments to the contractor. The principle of units of measurements normally consists the following: a) Single units work like doors, windows, trusses etc., are expressed in numbers. b) Works consists linear measurements involve length like cornice, fencing, hand rail, bands of specified width etc., are expressed in running metres (RM) c) Works consists areal surface measurements involve area like plastering, white washing, partitions of specified thickness etc., and are expressed in square meters (m2)
  • 8. 8 | P a g e SAQIB IMRAN 0341-7549889 8 d) Works consists cubical contents which involve volume like earth work, cement concrete, Masonry etc are expressed in Cubic metres. Table below shows units of measurement of various items of civil engineering works based on IS 1200. Sl. No. Particulars of item Units of measurement Units of payment 1 Earthwork 1. Earthwork in excavation CUM Per CUM 2. Earthwork in filling in foundation trenches CUM Per CUM 3. Earth work in filling in plinth CUM Per CUM 2 Concrete 1. Lime concrete in foundation CUM Per CUM 2. Cement concrete in lintels CUM Per CUM 3. RCC in slab CUM Per CUM 4. Cement concrete or RCC in chujja, sunshade CUM Per CUM 5. Lean concrete in roof terracing (thickness specified) SQM Per SQM 6. Cement concrete bed CUM Per CUM 7. Reinforced concrete sunshade (specified width and height) CUM Per CUM 3 Damp proof course (DPC) – thickness mentioned SQM Per SQM 4 Brick work 1. Brickwork in foundation CUM Per CUM
  • 9. 9 | P a g e SAQIB IMRAN 0341-7549889 9 2. Brickwork in plinth CUM Per CUM 3. Brickwork in super structure CUM Per CUM 4. Thin partition walls SQM Per SQM 5. Brickwork in arches CUM Per SQM 6. Reinforced brickwork CUM Per CUM 5 Stone work 1. Stone masonry CUM Per CUM 6 Wood work 1. Doors and windows frames or chaukhats, rafters, beams CUM Per CUM 2. Shutters of doors and windows (thickness specified) SQM Per SQM 3. Doors and windows fittings (like hinges, tower bolts, sliding bolts, handles) Each Per Each 7 Steel work 1. Steel reinforcement bars etc. in RCC and reinforced brick work Quintal Per Quintal 2. Bending, binding of steel reinforcement Quintal Per quintal 3. Rivets, bolts and nuts, anchor bolts, lewis bolts, holding down bolts Quintal Per quintal 4. Iron hold fasts – – 5. Iron railing (height and types specified) – – 6. Iron grills SQM Per SQM 8 Roofing
  • 10. 10 | P a g e SAQIB IMRAN 0341-7549889 10 1. RCC and RB slab roof (excluding steel) CUM Per CUM 2. Lean concrete roof over and inclusive of tiles or brick or stone slab etc. (thickness specified) SQM Per SQM 3. Centering and shuttering formwork SQM Per SQM 4. AC sheet roofing SQM Per SQM 9 Plastering, points and finishing 1. Plastering – cement or lime mortar (thickness and proportion specified) SQM Per SQM 2. Pointing SQM Per SQM 3. White washing, color washing, cement washing, (number of coats specified) SQM Per SQM 4. Distempering (number of coats specified) SQM Per SQM 5. Painting, varnishing (number of coats specified) SQM Per SQM 10 Flooring 1. 25mm cement concrete over 75mm lime concrete floor (including lean concrete) SQM Per SQM 2. 25mm or 40mm cement concrete floor SQM Per SQM 3. Doors and window sills (CC or cement mortar plain) SQM Per SQM 11 Rain water pipe / plain pipe RM Per RM 12 Steel wooden truss Each Per each 13 Glass panels (supply) SQM Per SQM 14 Fixing of glass panels or cleaning Each Per Each Note:
  • 11. 11 | P a g e SAQIB IMRAN 0341-7549889 11  SQM = Square meter  CUM = Cubic meter  RM = Running meter Methods for Measurement of civil engineering works: The rules for measurement of each item are invariably described in IS – 1200. However some of the general rules are listed below: 1. Measurement shall be made for finished item of work and description of each item shall include materials, transport, labour, fabrication tools and plant and all types of overheads for finished the work in required shape, size and specification. 2. In booking, the order shall be in sequence of length, breadth and height or thickness. 3. All works shall be measured subject to the following tolerances.  Linear measurement shall be measured to the nearest 0.01m.  Areas shall be measured to the nearest 0.01 SQM  Cubic contents shall be worked out to the nearest 0.01 cum. 4. Same type of work under different conditions and nature shall be measured separately under separate items. 5. The bill of quantities shall fully describe the materials, proportions, workmanships and accurately represent the work to be executed. 6. In case of masonry (stone or brick) or structural concrete, the categories shall be measured separately and the heights shall be described as:
  • 12. 12 | P a g e SAQIB IMRAN 0341-7549889 12  From foundation to plinth level  From plinth to first floor level  From first floor to second floor level and so on. Units of Measurement for Payments of Civil Construction Works Units of Measurements for payment of construction works in civil engineering projects are given in table below: Sl. No. Civil Construction Works Units of measurement Unit of payment 1 Earthwork: Excavation, filling, cutting, banking m3 100 m3 2 Surface dressing m2 m2 3 Cutting of trees Number Per number 4 Stones: quarrying, blasting m3 m3 5 Concrete: PCC, RCC, Precast m3 m3 6 Jail works m2 m2 7 Damp proof course m2 m2 8 Brick work of any description m3 m3 9 Thin partition wall m2 m2 10 String course, drip course, water course coping etc. m m 11 Stone work of any description m3 m3
  • 13. 13 | P a g e SAQIB IMRAN 0341-7549889 13 12 Stone work in wall facing (thickness specified) m2 m2 13 Wood work: truss, rafter, beam etc. m3 m3 14 Door, window shutters m2 m2 15 Door, window fittings Number Per number 16 Timbering, boarding, sawing of timber, timbering of trenches, partition, etc. m2 m2 17 Steel work Quintal Per quintal 18 Expanded metal, fabric reinforcement, cutting angles, plates, tees cm2 cm2 19 Threading; welding; solder of sheets cm Per cm 20 Iron gate, grill collapsible gate, rolling shutter m2 m2 21 Iron railing m m 22 Roofing: tiled, corrugated iron, caves board (thickness specified) m2 m2 23 Centering, shuttering m2 m2 24 Ridges; valleys; gutters (girth given) m m 25 Expansion and contraction joints m m 26 Ceiling timber, A.C. sheet, board, etc. m2 m2 27 Plastering; pointing; white washing; distempering; painting; varnishing; polishing; coal tarring; removing of paints m2 m2 28 Flooring of any kind m2 m2 29 Pipes, laying of pipes m m
  • 14. 14 | P a g e SAQIB IMRAN 0341-7549889 14 30 Dismantling of brick masonry m3 m3 31 Grouting m2 m2 32 Grouting of cracks, joints m m 33 Supply of sand; brick ballast; aggregates; timber m3 m3 34 Supply of cement Bag Per bag 35 Supply of steel, G.I. sheet, bare electric line Quintal Per quintal 36 Supply of GI sheet m2 m2 37 Supply of sanitary items Number Per number 38 Supply of paint, varnishes Liter Per liter 39 Supply of explosives, stiff paint Kg Per kg Measurement of Masonry Brick Works in Construction including Deductions Measurement of masonry works in construction is required for calculation of quantities of materials in masonry and to measure completed work. Masonry works are those where cement and fine aggregates without any coarse aggregates are used for construction purpose. There different types of masonry work: 1. Brick Masonry 2. Concrete block / brick masonry 3. Stone / rubble masonry
  • 15. 15 | P a g e SAQIB IMRAN 0341-7549889 15 4. Clay tiles, etc. Measurement of Masonry Works: Masonry works are such as brick masonry, concrete block, stone or rubble masonry are generally measured in volume, but are also measured in terms of area where the thickness of masonry is limited to single brick or single block. Tiling is measured in area. While measuring the quantities of masonry work, the wastage of materials such as bricks, cement or sand is not taken into account. Also, the types and classes of bricks, blocks or tiles are not considering while measuring the quantity of work. This is taken care in pricing of the different masonry works. Each type of masonry works are measured separately into categories to calculate exact cost of construction based on its price.
  • 16. 16 | P a g e SAQIB IMRAN 0341-7549889 16 Rules for Measurement of Masonry Works: Following are the general rules for measuring masonry works: 1. Masonry is measured as “net in place” with deductions for openings such as doors, windows, ventilation etc. 2. Different shapes of masonry units are measured separately such rectangular, circular etc. 3. Masonry at different heights are measured separately because masonry at higher elevation from ground may require scaffolding and hoisting. 4. Masonry work is measured separately in the different categories such as: a) Facings b) Backing to facings c) Walls and partitions d) Furring to walls e) Fire protection 5. Masonry work which requires cleaning of surface are measured in area such as square meter or square feet. 6. Any special treatment to masonry surfaces are measured in area such as square feet or square meter, with the count of number of coats applied. 7. Any joints in masonry structure such as expansion joints or control joints are measured in length such as meter or feet with description of type of
  • 17. 17 | P a g e SAQIB IMRAN 0341-7549889 17 joint. Also the type of joint filler material for the joint used is indicated in description. 8. For different types of mortar, or mortar with different types of admixtures are measured separately. These are measured in volume such as cubic meter or cubic feet. 9. If any reinforcement is used in masonry, then it is measured separately. 10. Extra items in masonry construction such as anchor bolts, sleeves, brackets, and similar items that are built into masonry are described in the measurement and measured separately. 11. Enumerate weep holes where they are required to be formed using plastic inserts and such like. 12. Measure rigid insulation to masonry work in square feet or square meters, describing the type and thickness of material. Measurement of Brick Masonry For measurement of brick masonry, general rules specified above are used along with following points: 1. Brick masonry is measured in volume for thickness more than single bricks. For masonry with single bricks, it is measured in square meters. 2. Facing bricks are measured separately. 3. Different types or class of brick masonry are measured separately.
  • 18. 18 | P a g e SAQIB IMRAN 0341-7549889 18 Measurement of Concrete Block Masonry Concrete block masonry are measured as general rules described above along with following points: 1. Different types of concrete block masonry such as type and size of concrete blocks are measured separately. 2. Special units required at corners, jambs, heads, sills, and other similar locations are measured separately. 3. Measure concrete to core fills and bond beams in cubic feet or cubic meters, stating the strength and type of concrete to be used. These are measured separately for different types of concrete block based on strength. 4. Measure in linear feet or meters reinforcing steel to core fills and bond beams, stating the size and type of rebar to be used. Deduction for Openings and Bearings in Masonry Works Measurements No deduction is made for following: (1) Opening each up to 1000sq cm 0.1 square meter (2) Ends of beams, post, rafters, etc. up to 500 sq.cm or 0.05 sq.m in section. (3) Bed plate, wall plate, bearing of balcony (chajja) and the like up to 10 cm depth. bearing of floor and roof slabs are not deducted from masonry. For other openings deduction are made in following manner:
  • 19. 19 | P a g e SAQIB IMRAN 0341-7549889 19 Deductions for Rectangular Opening: Full deduction is made for rectangular openings in masonry walls Deductions = L x H x thickness of wall Deductions for Reinforced Concrete and Reinforced Brickwork: Reinforced concrete and reinforced brickwork may be in roof or floor slab, in beam lintel, column, foundation etc and the quantities are calculated in cubic meter. Length, breadth and thickness are taken correctly from the plan, elevation and section or from other detailed drawings. The quantities are calculated in cubic meter exclusive of steel reinforcement and its bending but inclusive of centering and shuttering and fixing and binding reinforcement in position. The reinforcement including its bending is taken up separately under steel work in as per weight. For this purpose, 0.6% to 1% (usually 1%) of R.C.C. or reinforced brickwork by volume may be taken for steel if other details are not available. The volume of steel is not required to deducted from R.C.C. or reinforced brick work.
  • 20. 20 | P a g e SAQIB IMRAN 0341-7549889 20 Reinforced concrete and reinforced brickwork may also be estimated inclusive of steel and centering and shuttering for the complete work, if specified. Centering and shuttering are usually included in the R.C.C or R.B. work but may also be taken separately as per square meter of surface in contact with concrete. Deductions for Flooring and Roofing Works: Ground floor: The base line concrete and floor finishing of cement concrete or stone or marble or mosaic etc. are usually taken as one job or one item and the quantity is calculated in square meter multiplying the length by the breadth. The length and breadth are measured as inside dimensions from wall to wall of superstructure. both the work of base concrete and floor finishing are paid under one item. Roof: Supporting structure is taken separately in cubic meter and the lime concrete terracing is computed in square meter with thickness specified under a separate item including surface rendering smooth. The compacted thickness of lime concrete terracing is 7.5 cm to 12 cm average. Lime concrete terracing may also be calculated in cubic meter with average thickness. Plastering: Plastering usually 12mm thick is calculated in square meter. for wall the measurement are taken for whole face of the wall for both side as solid, and deducting for opening are made in following manner.
  • 21. 21 | P a g e SAQIB IMRAN 0341-7549889 21 (1) No deduction is made for the end of beams, posts, rafters etc. (2) For small opening up to 0.5 square meter no deduction is made, and at the time no additions are made for jambs, soffits and sills of these opening. (3) For opening exceeding 0.5 square meter but not exceeding 3 square meter deduction is made for one side and other face is allowed for jambs soffits and sills which are not taken into account separately (4) For opening above 3 square meter deduction is made for both faces of the opening and the jambs, soffits and sills are into account and added. Pointing: Pointing in wall calculated in square meter for whole surface and deduction similar to plastering is made. Cornice: Ornamental and large cornice is measured in running meter or running foots for the complete work which includes masonry, plastering, moldings etc. and paid for in running meter. Similarly, string course, corbelling, coping etc are measured and paid for in running meters for the complete work. Pillars: Pillars are taken separately in cubic meter foe their net volume and quantities are calculated. Wood Works:
  • 22. 22 | P a g e SAQIB IMRAN 0341-7549889 22 Wooden beams, posts, wooden roof trusses, doorpost etc. come under this items and the quantities are computed in cubic meter. The dimension of finished work shall be taken. Iron Works: This computed weight in kg or quintal and the quantities are calculated correctly by multiplying the weights per running meters by length. the weight per running meter can be obtained from the steel section book. For steel joint the length is equal to the clear span plus two bearing the bearing may taken third forth thickness of wall or 20 to30 cm. White Wash or Color Washing or Distempering: The quantities are computed in square meter and are usually same as for plastering. The inside is usually white washed or distempered and this item will be same as for outside plaster. These item need not be calculated separately but simply written as same as for outside plaster and inside plaster. Brick calculator | Brickwork calculation and brick estimation In this article i will tell you how to calculate bricks in a wall. By the explanation describe below, you can make your own MS Excel Brick calculator program to calculate bricks in a wall.
  • 23. 23 | P a g e SAQIB IMRAN 0341-7549889 23 1. We know that standard dimensions of brick is 9 inch x 3 inch x 4.5 inch. 2. Convert these dimensions into feet. 3. Now multiply these dimensions to get volume of a brick. 4. 0.75 feet x 0.25 feet x 0.375 feet = 0.0703125 cubic feet. 5. Bricks required for 1 cubic feet brickwork will be (1/0.070) = 14.285 bricks 6. 10% space of brickwork is covered by mortar. 7. Subtract 10% bricks from 14.285, 14.285-1.4285=12.85 bricks. 8. Add 5% wastage of bricks. 9. 5% of 12.85 is 0.64 bricks. 10.Add 0.64 and 12.85 to get number of bricks in 1 cubic feet, we get 0.64 + 12.85 =13.492 bricks or we can say that 13.5 bricks. Number of bricks in 100 Cubic feet brickwork As we know that there are 13.5 bricks in 1 cubic feet. So in 100 cubic feet there will be 1350 bricks.
  • 24. 24 | P a g e SAQIB IMRAN 0341-7549889 24 Bricks per square foot Wall thickness Bricks per square foot 4.5 inch 5.0625 bricks 9 inch 10.125 bricks 13.5 inch 15.1875 bricks Bricks per square meter Wall thickness Bricks per square meter 4.5 inch 57.16 bricks 9 inch 114.329 bricks 13.5 inch 171.49 bricks How to calculate bricks in a wall ? To calculate bricks in a wall, we need to know the dimensions of the wall. For instance, if a wall is 10 feet long with 10 feet height and 9 inch thickness. Then we can find its bricks in a following way. Multiply dimensions of wall. 10 feet x 10 feet x 0.75 feet. We will get 75 cubic feet. We have seen above that there are 13.5 bricks in 1 cubic feet brickwork. So there will be 75 x 13.5 =1012.5 bricks in 75 cubic feet. In this way we calculate bricks in any wall with the known dimensions. Bricks calculation formula Bricks calculation formula is written below. In feet  Length of wall in feet x height of wall in feet x thickness of wall in feet x 13.5 = number of bricks
  • 25. 25 | P a g e SAQIB IMRAN 0341-7549889 25 In meter  length of wall in meter x height of wall in meter x thickness of wall in meter x 500 = number of bricks Number of bricks in 1 Cubic meter brickwork Standard dimensions of brick in metric units are 225 x 112.5 x 75 mm. 1. multiply these dimensions to get volume of a brick, 0.225 m x 0.1125 m x 0.075 m=0.00189 cubic meter. 2. In one cubic meter, number of bricks will be (1/0.00189)=529.1 bricks. 3. 10% of brickwork will be covered by mortar. 4. Subtract 10% bricks from the 529.1, we will get 529.1-52.91=476.20 bricks. 5. Add 5% wastage of bricks. 6. 5% of 476.20 is 23.80 bricks. 7. Add 23.80 and 476.20 to get number of bricks in one cubic meter brickwork. 8. 23.80+476.20=500 bricks.
  • 26. 26 | P a g e SAQIB IMRAN 0341-7549889 26 Standard conversion factors INCH = 25.4 MILLIMETRE FOOT = 0.3048 METRE YARD = 0.9144 METRE MILE = 1.6093 KILOMETER ACRE = 0.4047 HECTARE POUND = 0.4536 KILOGRAM DEGREE FARENHEIT X 5/9 – 32 = DEGREE CELSIUS MILLIMETRE= 0.0394 INCH METRE = 3.2808FOOT METRE = 1.0936YARD 1) MILD STEEL (MS) SHEET WEIGHT (KGS) = LENGTH (MM) X WIDTH (MM) X 0. 00000785 X THICKNESS example – The weight of MS Sheet of 1mm thickness and size 1250 MM X 2500 MM shall be 2500MM X 1250 MM X 0.00000785 X 1 = 24.53 KGS/ SHEET ROLLED STEEL CHANNELS MS SQUARE WEIGHT (KGS ) = WIDTH X WIDTH X 0.00000785 X LENGTH. Example : A Square of size 25mm and length 1 metre then the weight shall be. 25x25X 0.00000785 X 1000mm = 4.90 kgs/metre MS ROUND WEIGHT (KGS ) = 3.14 X 0.00000785 X ((diameter / 2)X( diameter / 2)) X LENGTH. Example : A Round of 20mm diameter and length 1 metre then the weight shall be. 3.14 X 0.00000785 X ((20/2) X ( 20/2)) X 1000 mm = 2.46 kgs / metre
  • 27. 27 | P a g e SAQIB IMRAN 0341-7549889 27 SS ROUND DIA (mm) X DIA (mm) X 0.00623 = WEIGHT PER METRE SS / MS Pipe OD ( mm) – W.Tthick(mm) X W.Thick (mm) X 0.0248 = Weight Per Metre OD ( mm) – W.Tthick(mm) X W.Thick (mm) X 0.00756 = Weight Per Foot SS / MS CIRCLE DIA(mm) X DIA (mm) X THICK(mm) 0.0000063 = Kg Per Piece SS sheet Length (Mtr) X Width (Mtr) X Thick(mm) X 8 = Weight Per Piece Length (ft) X Width (ft) X Thick(inch) X 3 /4 = Weight Per Piece S.S HEXAGONAL BAR DIA (mm) X DIA (mm) X 0.00680 = WT. PER Mtr Dia (mm) X Dia (mm) X 0.002072 = Wt. Per foot. BRASS SHEET WEIGHT (KGS) = LENGTH (MM) X BREADTH (MM) X 0. 0000085 X THICKNESS Example – The weight of brass sheet of thickness 1 mm, length 1220mm and breadth 355mm shall be 1220 X355X 0.0000085 X 1 = 3.68 Kgs/Sheet Following table shows how can we convert various most commonly used units from one unit system to another. Units to convert Value Square foot to Square meter 1 ft² = 0.092903 m² Foot per second squared to Meter per second squared 1 ft² = 0. 3048 m² Cubic foot to Cubic meter 1 ft³ = 0.028316 m³ Pound per cubic inch to Kilogram per cubic meter 1 lb/in³ = 27679.9 047102 kg/m³ Gallon per minute = Liter per second 1 Gallon per minute = 0.0631 Liter per second Pound per square inch = Kilopascal 1 Psi (Pound Per Square Inch) = 6.894757 Kpa (Kilopascal) Pound force = Newton 1 Pound force = 4.448222 Newton Pound per Square Foot to Pascal 1 lbf/ft2 = 47.88025 Pascal Acre foot per day = Cubic meter per second 1 Acre foot per day= 1428 (m3/s) Acre to square meter 1 acre = 4046.856 m² Cubic foot per second = Cubic meter per second 1 ft³/s = 0.028316847 m³/s
  • 28. 28 | P a g e SAQIB IMRAN 0341-7549889 28 Measurement units and standards are different in different countries but to maintain a standard, SI units are mostly used when dealing with projects involving different countries or even different states. Small projects can be done with the locally used unit system but when the project is big, one standard unit system is to be used. Two most common system used in the United States are  United States Customary System (USCS) System International (SI) But the SI unit system is more widely used all over the world. Following is the table which shows how you can convert USCS measurements in SI measurements. ( Just multiply the USCS amount with the corresponding figure given in table below Convert USCS into SI Units USCS unit X Factor = SI unit SI symbol Square foot X 0.0929 = Square meter M2 Cubic foot X 0.2831 = Cubic meter M3 Pound per square inch X 6.894 = Kilopascal KPa Pound force X 4.448 = Newton Nu Foot pound torque X 1.356 = Newton meter N-m Kip foot X 1.355 = Kilonewton meter LN-m Gallon per minute X 0.06309 = Liter per second L/s Kip per square inch X 6.89 = Megapascal MPa BASIC STANDARDS: 1 inch = 25.4 millimeters = 2.54cm. 1 meter = 39.37 inches =1.09 yards. 1 liter = 0.22 galls (imp.) 1 gallon (imp.) = 4.546 liters. 1 gallon (US) = 3.785 liters. 1 Kilogram (kg) = 2.2046 pounds (lb). METRIC UNIT OF WEIGHT/MASS: 1 tonne = 1000 kilograms = 1,000,000 grams. 1 quintal = 100 kilograms = 100,000 grams. 1 Slug = 14.606 kg 1 Slug = 32.2 lb MEASUREMENTS OF LENGTH: 1 foot = 12 inches. 1 yard = 3 feet. 1 furlong = 220 yards. 1 mile = 8 fulongs.
  • 29. 29 | P a g e SAQIB IMRAN 0341-7549889 29 1 Kilometer (Km) = 1000 meters. 1 meter (m) = 100 centimeters (cm). 1 cm = 10 millimeter (mm). METRIC UNITS FOR LIQUID MEASUREMENTS: 1 liter = 1000ml. 1 liter = 1kg. 1 kiloliter (1000 liters) = 1 cubic meter/ 1 cu.m/ 1 m3. CONVERSION FACTORS: 1 cu. ft. = 28.317 liters. 1 cu. ft. = 0.028 cu. meters. 1 cu. ft. = 6.24 galls (imperial). 1 cu. ft. = 7.48 galls (US). 1 imp. gall = 1.20 galls (US), liquid. 1 imp. gall = 1.03 galls (US), dry. MEASUREMENTS OF AREA: 1 Acre = 43560 sq. ft 1 Acre = 4046.46 sq. m 1 Acre = 8 Kanals. 1 Kanal = 20 Marlas. 1 Marla = 225 sq. ft (* in some regions 272 sq. ft) 1 Marla = 15.50 sq.m MISCELLENIUS CONVERSION FACTORS: 1 cu.m = 35.32 cu.ft. 1 Pound = 4.448 Newton (Force). 1 klb = 4.448 kN. 1 Psi (lb/sq.in) = 6.689 Pascal (N/sq.m) 1 (lb/sq. ft) = 0.048 (kN/sq.m) CALCULATION OF UNIT WEIGHT OF STEEL BARS:
  • 30. 30 | P a g e SAQIB IMRAN 0341-7549889 30 After estimating it is very important to know the unit weight of steel bars because, we estimate as 100 meter 20mm ø bar or 100 feet 16mm ø bar, etc (ø is the symbol of diameter). But steel bar suppliers will not understand this notation, they measure the steel bars in weight. So we have to order them in kg or quintal or ton. In this article, we will discuss how to calculate unit weight of steel bars of different diameter. The formula is W = D²L/162 Where W = Weight of steel bars. D = Diameter of steel bars in mm. L = Length of bars in meter. Example 1: Calculate the weight of 60 meters long 12 mm ø bar. Here, D = 12 mm. L= 60 m. We know that, W = D²L/162 W = 12² x 60/162 = 53 kg Weight of 60 m 12mm ø bar is 53 kg. Let’s look for another example. Example 2: Calculate the weight of 100 m 16 mm ø bar. Here, D = 16 mm. L = 100 m. W = 16² x 100/162 = 158 kg. If we put 1 meter length for each diameter of steel bar in the formula then we will get the unit weight.  10mm ø bar = 10² x 1/162 = 0.617 kg/m  12mm ø bar = 12² x 1/162 = 0.888 kg/m  16mm ø bar = 16² x 1/162 = 1.580 kg/m  20mm ø bar = 20² x 1/162 = 2.469 kg/m If we multiply the length of bars with this unit weight we will get the total weight of steel bars. For example, total weight of 1000 meter long 20mm ø steel bar is, 1000 x 2.469 = 2469 kg. Using the same method we can calculate the unit weight of different steel bars.
  • 31. 31 | P a g e SAQIB IMRAN 0341-7549889 31 Here I have calculated in meter but we can also calculate in foot. To calculate in foot we have to use the following formula: W= D²L/533 Where D = Diameter of bars in mm. L = Length of bars in foot. HOW TO CALCULATE STEEL QUANTITY FOR RCC BEAM, COLUMN AND SLAB Following are the steps to calculate the quantity of steel for RCC slab 1. Prepare a bar bending schedule in order to classify different shapes of bars (bent up bar, straight anchor bar, eos bar, curtail bar etc) and diameters. 2. List down all the shapes of bars from the drawing. 3. Count the number of bars of each of those shapes. 4. Then calculate the cutting length of each of those bars. Cutting length of bar = (length of the member – deduction for cover on both sides) + development length. 5. Then calculate the unit weight of each dia bars by the following formula: W = d^2/162 Where d is the dia in mm and weight (w) in kg. 6. Then calculate weight of rebar Weight of rebar= no of bars x cutting length x unit weight 7. Add all the weight to get the total steel quantity. NOTE – 1. Minimum % of steel as per Indian standard are: 1. Beam (Teinsion reinforcement): As = 0.85bd/fy of gross cross-section area. 2. Slab – 0.12% of total area 3. Column – 0.8% of cs area 2. Maximum % steel as per Indian standard are: Beam – 4 % of cross-section area. Slab – 4% of cross-section area. column — 6% of cross-section area. 3. . Development Length is usually specified in the drawings, but if not thenyou can calculate it as, D.L = Depth – 2 times cover 4. Binding wire = 10 grams per kg of reinforcement. 5. No. of stirrups = (length of member – 2 x cover ) / spacing + 1
  • 32. 32 | P a g e SAQIB IMRAN 0341-7549889 32 WHAT IS BAR BENDING SCHEDULE? Bar bending schedule commonly known as BBS is one of the most important terms in Civil Engineering. Because it plays a vital role in building construction. Like other building materials estimation of steel is also required for constructing a building and here BBS comes with an easy solution. Bar bending schedule provides the reinforcement calculation and some other important details such as bar mark, bar diameter, bar shape, cutting length, number of bars, the weight of bar, total weight of steel etc. So that we can order the required amount of steel in advance. HISTORY OF BAR BENDING SCHEDULE: Long years back when there was no today’s bar bending schedule, certain recommendations given by Prof. BN Dutta were used for estimating steel for different components of a building. But these are now backdated (not wrong) and we don’t use them in today. Because No accurate values were specified if we use more bars in a single member. Nowadays we are constructing 150+ floors building. It is now possible with our modern techniques, equipment etc. Estimation of steel becomes easier because of BBS. Civil engineers who are working on site or freshers who are going to work at construction sites must know how to prepare bar bending schedule. In this article, I will discuss some important things used in preparing bar bending schedule. These are just the basic things. In future, I will come up with some other articles related to BBS such as BBS for beams, columns, slabs, footings etc. HOOK LENGTH: The hook is the extra length left at the 4th corner of a stirrup so that the stirrup retains its shape. Generally, hook length is taken as 9d for one side. Where d = Diameter of the bar.
  • 33. 33 | P a g e SAQIB IMRAN 0341-7549889 33 The total length of stirrups = Total length of the bar + 2 x hook length (for two hooks) = L + 2 x 9d = L + 18d. Where L = length of the bar for stirrup. BEND LENGTH: The bar is bent at the column end to tie with the footings. This extra length for bend is called bend length. Bend length is generally considered as 16 d Bend Length = 16d DEVELOPMENT LENGTH: Development length is the length of bar required for transferring the stress into concrete.
  • 34. 34 | P a g e SAQIB IMRAN 0341-7549889 34 In simple words, the quantity of the rebar length that is actually required to be embedded into the concrete to create the desired bond strength between steel and concrete and furthermore to produce required stress for the steel in that area. The formula for development is given below: Development length (Ld) = d x σs/τbd Where d = Diameter of the bar. σs = Stress in the bar at the section considered as design load τbd = Design bond stress. LAP LENGTH: Lap length is the overlapping length of two bars side by side which gives required design length. In RCC structure if the length of a bar is not sufficiently available to make design length, lapping is done. Suppose we need to build a 20 m tall building. But is there any 20 m bar available in the market? No, the maximum length of rebar is usually 12 m, so we need to join two bars to get 20 m bar. Lap length for tension members = 40d Lap length for compression members = 50d. d = Diameter of bars.
  • 35. 35 | P a g e SAQIB IMRAN 0341-7549889 35 Look at the image below. You may be seen this on the terrace (top floor) of buildings. This extra rebar is left for future construction purpose. I hope you understand this. CRANK LENGTH: Generally, bars are bent near the support at an angle of 45°. The angle of bend may also be 30° in shallow beams. The purpose of bend near the support is firstly to resist the negative bending
  • 36. 36 | P a g e SAQIB IMRAN 0341-7549889 36 moment which occurs in the region of the support and secondly to resist the shear force which is greater at the support. Crank bars are mostly provided in slabs. Crank length = D/sin45° – D/tan45° =1.42D – D = 0.42D So Crank Length = 0.42D Where D = Clear height of the bar = Thickness of slab – (Top cover + Bottom cover) – Diameter of the bar UNIT WEIGHT OF STEEL: The weight of bar is calculated by the following formula W = d²L/162 Where W = Weight of bars. L = Length of bars in meter. d = Diameter of the bar. Example: Calculate the weight of 20 meters long 16 mm ø bar W = 16² x 20/162 = 32 kg. CUTTING LENGTH OF BENT UP BARS IN SLAB: As a site engineer, you need to calculate the cutting length of bars according to the slab dimensions and give instructions to the bar benders. For small area of construction, you can hand over the reinforcement detailing to the bar benders. They will take care of cutting length. But beware, that must not be accurate. Because they do not give importance to the bends and cranks. They may give some extra inches to the bars for the bends which are totally wrong. So it is always recommended that as a site engineer calculate the cutting length yourself. In this article, we will discuss how to the calculate length for reinforcement bars of slab. Let’s start with an example. EXAMPLE:
  • 37. 37 | P a g e SAQIB IMRAN 0341-7549889 37 Where, Diameter of the bar = 12 mm Clear Cover = 25 mm Clear Span (L) = 8000 Slab Thickness = 200 mm Development Length(Ld) = 40d CALCULATION: Cutting Length = Clear Span of Slab + (2 x Development Length) + (2 x inclined length) – (45° bend x 4) – (90° bend x 2) Inclined length = D/(sin 45°) – dD/ (tan 45°) = (D/0.7071) – (D/1)= (1D – 0.7071D)/0.7071= 0.42 D As you can see there are four 45°bends at the inner side (1,2,3 & 4) and two 90° bends ( a,b ). 45° = 1d ; 90° = 2d Cutting Length = Clear Span of Slab + (2 X Ld) +(2 x 0.42D) – (1d x 4) – (2d x 2) [BBS Shape Codes] Where, d = Diameter of the bar. Ld = Development length of bar. D = Height of the bend bar.
  • 38. 38 | P a g e SAQIB IMRAN 0341-7549889 38 In the above formula, all values are known except ‘D’. So we need to find out the value of “D”. D = Slab Thickness – (2 x clear cover) – (diameter of bar) = 200 – (2 × 25) – 12 = 138 mm Now, putting all values in the formula Cutting Length = Clear Span of Slab + (2 x Ld) +(2 x 0.42D) – (1d x 4) – (2d x 2) = 8000 + (2 x 40 x 12) +(2 x 0.42 x 138) – (1 x 12 x 4) – (2 x 12 x 2) ∴ Cutting Length = 8980 mm or 8.98 m. So for the above dimension, you need to cut the main bars 8.98 m in length. BAR BENDING SCHEDULE OF LINTEL BEAM: In this article, I will discuss how to prepare BBS of RCC Lintel Beam. 1. Calculate Total Length Of Main Bars: Length of 1 bar = Length of lintel – clear cover for both sides = 2500 – 2 x 25 [Clear cover for both sides] =2450 mm = 2.4 m. Length of 4 bars = 2.4 x 4 = 9.6 m 2. Calculate Weight Of Steel For Main Bars:
  • 39. 39 | P a g e SAQIB IMRAN 0341-7549889 39 Weight of steel for 12 mm bar = D²L/162 = 12² x 9.6/162 = 8.53 kg. 3. Calculate No Of Stirrups: No of stirrups = (Total length of lintel/c/c distance between strriups) + 1 = (2500/150) + 1 = 18 4. Calculate Total Length Of Stirrups: Inner depth distance = 150 -25 -25 -8 =84 mm Width distance = 150 – 25 – 25 -8 = 84 mm. Cutting length of stirrups =(2x Inner deoth diatance) +(2xWidth depth) + Hooks Length – Bend Hooks length = 10d Bend = 2d We have 2 hooks and 5 bend So, Cutting length of stirrups = (2×84) + (2 x84) +2x10x8 -5x2x8 = 418 mm = 0.418 m Total length of stirrups = 0.418 x 18 = 7.54 m 5. Calculate Weight Of Steel For Stirrups: Weight of steel for stirrups = D²L/162 = 8² x 7.54/162 = 7.61 kg. Total weight of steel for lintel = 8.53 + 7.61 = 16.14 kg. THE FORMULA D²L/162 FOR CALCULATING WEIGHT OF STEEL BARS FULLY DERIVED THE FORMULA D²L/162 FULLY DERIVED: To calculate the weight of steel bars you must use the formula D²L/162, but do you know where the formula D²L/162 came from? Okay, no problem if you don’t know. In this article, I will share how to derive the formula D²L/162. So let’s start from the beginning. The formula is D²L/162 Where, D = Diameter of steel bar in millimeter L = Length of steel bars in meter Calculation Of The Formula D²L/162: We know that, Weight= Cross sectional area x Length x Density For steel bar, this also remains same. The weight of steel bars= Cross sectional area of steel bar x Length of steel bar x Density of steel bar. That means, W = A x L x ρ
  • 40. 40 | P a g e SAQIB IMRAN 0341-7549889 40 Where, W = Weight of steel bars A = Area = πD²/4 π (pi) = 3.14 D = Diameter of steel bar in millimeter L = Length of steel bar in meter ρ (Rho) = Density of steel bar = 7850 kg/m³ Therefore, W = 3.14 x D²/4 x L x 7850 But there is two conflicting unit in the formula. Which is millimeter for D and meter for ρ (Rho). So we need to convert either D or ρ to the same unit. Let’s change the unit of D from millimeter to meter. 1 millimeter = 0.001 meter Let’s put this into the formula, W= 3.14 x {(D² x 0.001 x 0.001)/4} x L x 7850 = D²L/162 Hope you all understood this calculation. Using this formula we can easily calculate the weight of steel bars. 10 + THUMB RULES FOR CONCRETE MIX DESIGN FOR ADDING 4 LITERS OF WATER IN 1 CU.M FRESHLY MIXED CONCRETE 1. The slump value will be increased by 25 mm. 2. The compressive strength of concrete will be decreased by 1.5 to 2.0 N/mm2 3. The shrinkage potential will be increased by 10%.
  • 41. 41 | P a g e SAQIB IMRAN 0341-7549889 41 4. 1/4 bag of cement will be wasted. IF THE TEMPERATURE OF FRESHLY MIXED CONCRETE IS INCREASED BY 1%, THEN 1. 4 liters of water per cu.m will give equal slump. 2. The air content will be decreased by 1%. 3. The compressive strength of concrete will be decreased by 1.0 to 1.5 N/mm2. IF THE AIR CONTENT OF FRESHLY MIXED CONCRETE IS 1. Increased by 1% then the compressive strength will be decreased by 5 %. 2. Decreased by 1%, yield will be decreased by 0.03 cu.m per 1 cu.m. 3. Decreased by 1%, then the slump value will be decreased about 12.5 mm. 4. Decreased by 1%, then the durability of the concrete will be reduced by 10%. CALCULATION OF MATERIALS FOR DIFFERENT MIX RATIO: Quantity estimation of materials is essentially required in any construction works and quantity of materials depend on the mix proportions of the concrete. In our previous article, we have already discussed how to calculate bricks in a wall. Today we will discuss how to calculate quantities of materials for different mix ratio of concrete. (Dry mix method) We will calculate quantities of materials for 1 m3 concrete (By volume). Let us assume the mix proportion is 1 : 2: 4 (cement:sand:stone =a:b:c) Volume of wet concrete = 1 m3 Volume of dry concrete = 1 × 1.54 = 1.54 m3 What Is 1.54 Given Below: CALCULATION FOR CEMENT: Formula, Cement = (Volume of dry concrete/a+b+c) × a = (1.54/a+b+c) × a = [(1.54/1+2+4)] × 1 = 0.22 cum Now density of cement = 1440 kg/cum ∴ Volume of cement = 0.22 × 1440 =316.8 kg. As we know, 1 bag of cement contains 50 kg of cement . ∴ Cement bags required = 316.8/50 = 6.33 bags.
  • 42. 42 | P a g e SAQIB IMRAN 0341-7549889 42 CALCULATION FOR SAND: Formula, Sand = (Volume of dry concrete/a+b+c) × b = (1.54/a+b+c) × b = (1.54/1+2+4) × 2 = 0.44 cum. CALCULATION FOR STONE CHIPS: Formula, Stone Chips = (Volume of dry concrete/a+b+c) × c = (1.54/a+b+c) ×c = (1.54/1+2+4) × 4 = 0.88 cum. CALCULATION FOR WATER CONTENT: Let us assume the water/cement ratio of the concrete is 0.45. w/c = 0.45 Required water for 1 bag cement = 0.45 × 0.0353 = 0.0159 cum. Where volume of 50 kg cement = 0.0353 cum 1 m3 water = 1000 Litre Required water for 1 bag cement=0.0159 × 1000 = 15.9 Litre. ∴ Required water for 6.33 bags cement = 6.33 × 15.9 = 101 Litre. SUMMARY: Cement = 6.33 bags. Sand = 0.44 cum Stone chips = 0.88 cum Water = 101 litre. Note: Yield of concrete is considered as 67% & Wastages of materials = 2% You can use the same formula for different mix proportions such as 1:1.5:3 etc. Here, we have used cubic meter unit but you can also calculate in cubic feet unit. UNIT WEIGHT OF BUILDING MATERIALS Unit Weight Of Building Materials: There are many building materials used in construction. In the below table we have tried to cover the unit weight of building materials which are most commonly used at the construction site. Material Unit Weight Water 1000 Kg/ m3 Bricks (broken) 1420 Kg/ m3 Bricks(common) 1600 Kg/ m3 Cement(ordinary) 1440 Kg/ m3 Cement (rapid hardening) 1250 Kg/ m3 Cement Mortar 2000 Kg/ m3 Cement Concrete (Plain) 2400 Kg/ m3
  • 43. 43 | P a g e SAQIB IMRAN 0341-7549889 43 Cement Concrete (Reinforced) 2500 Kg/ m3 Glass 2500 Kg/ m3 Lime Concrete 1900 Kg/ m3 Cement Plaster 2000 Kg/ m3 Lime Plaster 1700 Kg/ m3 Stones (Ballast) 1720 Kg/ m3 Stones (Aggregates) 1750 Kg/ m3 Stones (Basalt) 2850 Kg/ m3 Stones (Granite) 2450 Kg/ m3 Stones (Marble) 2650 Kg/ m3 Timber (Oak, Sal) 510 Kg/ m3 Timber (Mango) 650 Kg/ m3 Timber (Teak) 625 Kg/ m3 Coal 600 Kg/ m3 Plastics 1250 Kg/ m3 Oils 800 Kg/ m3 Ashes 650 Kg/ m3 Clinker 750 Kg/ m3 Rubber 1300 Kg/ m3 Slag 1500 Kg/ m3 Clay Soil 1900 Kg/ m3 Sand (dry) 1540 to 1600 Kg/ m3 Sand (wet) 11760 to 2000 Kg/ m3 Steel 7850 Kg/ m3 Chalk 2100 Kg/ m3 Bitumen 1040 Kg/ m3 CALCULATION OF BRICKS IN A WALL Estimation of building materials is essentially required before starting a new construction project. In our previous article, we have already discussed how to calculate cement, sand, and aggregates. Today we will discuss the easiest method to calculate the required number of bricks in a wall. So let’s start from the beginning.
  • 44. 44 | P a g e SAQIB IMRAN 0341-7549889 44 REQUIRED DATA: 1. Volume of the wall. 2. Volume of a standard brick. 3. Details of openings in the wall. PROCEDURE: 1. First, calculate the volume of the wall to be built: Let us assume, The length of the wall (l) = 10 foot. The height of the wall (h) = 10 foot. Thickness of the wall (b) = 1 foot. Calculate the volume of the wall by multiplying the length, height, and thickness. ∴ Volume of the wall = l×h×b = 10×10×1 =100 Cu.F 2. Calculate the volume of the brick: The standard size of a brick (IS Standard) is 190 mm ×90 mm ×90 mm and with the mortar joint, it becomes 200mm × 100 mm× 100 mm. l = 200 mm= 0.656168 ft. b = 100 mm =0.328084 ft. h = 100 mm = 0.328084 ft. ∴ Volume of the brick = l× b×h = 0.656168× 0.328084× 0.328084 = 0.0706 Cu.F 3. To find out the total nos of brick divide the volume of wall by the volume of the brick. ∴ No. of bricks required = 100/0.0706 = 1416 no. of bricks. Note: 1. Consider 10% wastages of bricks. 2. If the wall has any openings such as doors, windows etc subtract the volume of the openings from the volume of wall and then divide it by the volume of brick. HOW TO CALCULATE NUMBER OF CONCRETE BLOCKS IN A WALL
  • 45. 45 | P a g e SAQIB IMRAN 0341-7549889 45 Concrete Block Wall NUMBER OF CONCRETE BLOCKS IN A WALL: There are several methods for calculating number of blocks in a wall. In this article, I will explain two simple methods to find out total no. of blocks for a wall.  Surface area method.  Volume method. PROCEDURE: 1. CALCULATION BY SURFACE AREA METHOD: REQUIRED DATA: 1. Surface area of the wall. 2. Surface area of a standard concrete block. 3. Surface area of openings in the wall. STEP 1: Determine The Length & Height Of The Wall: Let, the Length of the wall = 10 feet. The height of the wall = 10 feet. STEP 2: Calculate The Surface Area Of The Wall: We know, Surface Area = Length x Height ∴ Surface area of the wall = 10 x 10 = 100 sq. feet. STEP 3: Calculate The Surface Area Of Openings: If the wall has any openings such as door, windows etc, calculate the surface area of openings. Let the wall has a window of 3′ x 3′
  • 46. 46 | P a g e SAQIB IMRAN 0341-7549889 46 ∴ Surface area of the window = 3 x 3 =9 sq. ft STEP 4: Substract The Surface Area Of Openings From Surface Area Of Walls: ∴ Final Surface Area of wall = 100 – 9 = 91 sq.ft. STEP 5: Calculate The Surface Area Of A Concrete Block With Mortar Allowance: Let the block is 16″ x 8″ x 8″ and mortar allowance is 1″ ∴ Surface Area of one block with mortar = (16+1) x (8+1)= 153 inch² = 153/12×12 = 1.0625 sq.ft STEP 6: Divide The Total Surface Area Of The Wall By Surface Area Of One Block: ∴ Number of blocks = Surface Area of wall/Surface Area of a block = 91/1.0625 = 86 Consider 5% wastage of concrete blocks. So the total numbers of blocks required = 86 + (86 x 5/100) = 86 + 4 = 90. 2. CALCULATION BY VOLUME METHOD: REQUIRED DATA: 1. Volume of the wall. 2. Volume of a standard concrete block. 3. Volume of openings in the wall. STEP 1: Determine The Width, Height, And Thickness Of The Wall: Let, the width of the wall = 10 feet. The height of the wall = 10 feet.
  • 47. 47 | P a g e SAQIB IMRAN 0341-7549889 47 The thickness of the wall = 8″ = 0.67 feet. [ Thickness of wall will be same as the thickness of one concrete block] STEP 2: Calculate The Volume Of The Wall: We know, Volume = Width x Height x Thickness ∴ Volume of the wall = 10 x 10 x 0.67 = 67 cubic feet. STEP 3: Calculate The Volume Of Openings: If the wall has any openings such as door, windows etc, calculate the volume of openings Let the wall has a window of 3′ x 3′ x 0.67′ [ Thickness of the window will be same as the thickness of the wall] ∴ Volume of the window = 3 x 3 x 0.67 =6 cu. ft STEP 4: Substract The Volume Of Openings From Volume Of Walls: ∴ Final volume of wall = 67 – 6 = 61 cu.ft. STEP 5: Calculate The Volume Of A Concrete Block With Mortar Allowance: Let the block is 16″ x 8″ x 8″ and mortar allowance is 1″ ∴ Volume of one block with mortar = (16+1) x (8+1) x 8 = 1224 inch3 [The mortal will be given on the upper side and one side of every concrete block] = 1224/12x12x12 = 0.70 cu.ft STEP 6: Divide The Total Volume Of The Wall By Volume Of One Block: ∴ Number of blocks = Volume of wall/Volume of a block = 61/0.70 = 86 Consider 5% wastage of concrete blocks. So the total numbers of blocks required = 86 + (86 x 5/100) = 86 + 4 = 90. Note: If the wall does not have any opening skip step 4, and just divide the surface area of wall by the surface area of one block. HOW TO CALCULATE QUANTITY OF MATERIALS IN ARCH In this article, I will discuss how two calculate quantity of materials in arch. 1. SEMI CIRCULAR ARCH: Given: Span = 8 ft Height = 4 ft Thickness = 1 ft
  • 48. 48 | P a g e SAQIB IMRAN 0341-7549889 48 Breadth = 1ft To calculate the quantity of materials in semi circular arch we need to calculate the volume of arch. Volume of arch = Cross-section of arch x Arch length We know Cross-section area = Thickness of arch x Breadth of arch = T x B From the above image, you can see the thickness and breadth are 1 ft. Cross-section of arch = 1 x 1 = 1 ft² Now Arch length = Circumference of half circle (The arch is semi circular) We know circumference of circle = 2πR Circumference of half circle = 2πR/2 = πR We don’t what is R. So we need to find out the ‘R’. R = Half span + Thickness/2 = 4 +1/2 = 4.5 ft. Arch length = πR =3.14 x 4.5 = 14.13 ft. Quantity of materials in arch = 1 x 14.13 = 14.13 cft. 2. SEGMENTAL ARCH: Given: Span = 8 ft Height = 2ft Thickness = 1 ft Breadth = 1ft Central angle = 105°
  • 49. 49 | P a g e SAQIB IMRAN 0341-7549889 49 SOLUTION: Volume arch = Cross-section of arch x Arch length We know Cross-section area = Thickness of arch x Breadth of arch = T x B Arch length = θπR/180 Now R = (a² + h²)/2h [a =half span = 8/2 =4] =(4² + 3²)/2 x 3 = 25/6 =4.16 ft. Arch length = (105 x 3.14 x 4.16)/180 = 7.61 Quantity of materials in arch = 1 x 7.61 = 7.61 cft. HOW TO CALCULATE SHUTTERING AREA FOR CONSTRUCTION
  • 50. 50 | P a g e SAQIB IMRAN 0341-7549889 50 Shuttering or formwork is a temporary, rigid structure in which the cast in situ concrete is poured for casting the members to required shape. Different formworks are used for different shape members. In this article, we will discuss how to calculate the shuttering area before construction. Before calculating the shattering area first, we need to know how to calculate the peripheral length of any shape. PERIPHERAL LENGTH/PERIMETER: We know that perimeter is the distance around a 2D (two dimensional) shape. For example, square has four sides. Let ‘s’ be the length of one side, then ∴ The peripheral length = s+s+s+s = 4s Rectangle has four sides also but the length and breadth is different, let one side length is ‘l’ and breadth is ‘b’ ∴ Peripheral length = l+b+l+b = 2l+2b Now coming to the calculation of shuttering area. Shttering area = Pheripheral length * Depth Let me give you an example
  • 51. 51 | P a g e SAQIB IMRAN 0341-7549889 51 Pheripheral length = (2 * 1) + (2*0.8) = 2 +1.6 =3.6 ∴ Total shuttering area = 3.6 * 4 = 14.4 sq.m HOW TO CALCULATE CEMENT BAGS IN 1 CUBIC METER PROCEDURE TO CALCULATE CEMENT BAGS IN 1 CUBIC METER: Let us consider the nominal mix is 1:2:4 Loss of cement is considered as 2% Output of mix is considered as 67% To achieve 1 cum output, we need 1/0.67 = 1.49 say 1.50 cum dry mix. Now add the wastage of 2%, i.e (1.50 + 0.02) = 1.52 cum. Volume of cement = (cement/cement+sand+aggregate) × Total material =(1/1+2+4) × 1.52 =0.2171 cum As we know, the density of cement is 1440 kg/cum and Weight of 1 bag cement = 50 kg. Therefore volume of 1 bag cement = 50/1440 =0.0347 cum. ∴ No. of cement bags required in 1 cubic meter = 0.2171/0.0347 = 6.25 bags. Note: You can use the same formula for calculating cement for other nominal mixes.
  • 52. 52 | P a g e SAQIB IMRAN 0341-7549889 52 QUANTITY OF CEMENT, SAND, & AGGREGATES FOR 1000 SQ FT SLAB To calculate the quantity of cement, sand, and aggregates required for a flat slab first we need to calculate the volume. Area of flat slab = 1000 sq.ft =93 sq. m. The minimum thickness provided for slab is 150mm .( According to IS 456) 150 mm = 0.15 metres Hence Wet volume = Area of slab x Thickness of slab Wet volume = 93 x 0.15 = 13.95 cu. m. To calculate the quantities of materials we need dry volume Dry volume = Wet volume x 1.54 Check why 1.54 is multiplied with wet volume to get dry volume. ∴ Dry volume = 13.95 x 1.54 = 21.48 cu.m (approximately). Generally, M20 grade concrete is predominantly used for construction purposes. M20 = 1: 1.5: 3 (Cement:Sand:Aggregates) = (a:b:c) QUANTITY OF CEMENT: Quantity of cement = Dry volume x (a/{a+b+c} Quantity of cement = Dry volume x (1/{1+1.5+3}) for M20 grade concrete. = 21.48 x (1/5.5}) = 3.90 cu.m = 3.90 cu.m We need the quantity of cement in terms of bags. So by multiplying the quantity of cement with the density of cement, we will the get quantity of cement in terms of kilograms. Unit weight or Density of cement = 1440 kg/cu.m. Quantity of cement in kg(s) = 1440 x 3.90 = 5616 kg We know that 1 cement bag = 50 kgs ∴ No. of cement bags required = 5616/50 kg = 112.32 bags =112 bags. QUANTITY OF SAND: Quantity of sand = Dry volume x (b/{a+b+c} ∴ Quantity of sand = Dry volume x (1.5/{1+1.5+3}) for M20 grade concrete. = 21.48 x (1.5/5.5}) = 5.85 cu.m QUANTITY OF AGGREGATES: Quantity of aggregates = Dry volume x (c/{a+b+c} ∴ Quantity of aggregates = Dry volume x (3/{1+1.5+3}) for M20 grade concrete. = 21.48 x (3/5.5}) = 11.71 cu.m SUMMARY: Cement = 112 bags. Sand = 5.85 cu.m
  • 53. 53 | P a g e SAQIB IMRAN 0341-7549889 53 Aggregates = 11.71 cu.m Note: ConsiderYield of concrete as 67% & Wastages of materials = 2% You can use the same formula for different mix proportions such as 1:2:4 etc. Here, we have calculated in cubic meter unit but you can calculate in cubic feet unit. HOW TO CALCULATE VOLUME OF CONCRETE FOR STAIRCASE: Staircase is one of the essential parts of a building. It helps people to access different floors in a building. In this article, I will explain how to estimate concrete volume and quantity of cement, sand, aggregates for a staircase. Before starting the estimation, we need to know different components of a staircase which I will use in this calculation. COMPONENTS OF STAIRCASE: STEPS: A portion of stairway comprising the tread and riser which permits ascent and descent from one floor to another. TREAD: The horizontal upper part of a step on which foot is placed in ascending or descending stairway. RISER: The vertical portion of a step providing support to the tread. FLIGHT: A series of steps without any platform, break or landing in their direction. LANDING: A platform or resting place provided between two flights. Now coming to the calculation of concrete volume for the staircase. Let’s take an example:
  • 54. 54 | P a g e SAQIB IMRAN 0341-7549889 54 The height of one floor = 12 feet. Height to be acquired by one flight = 12/2 = 6 feet. Risers = 6″ = 0.5 feet. Number of risers = Height of flight / Riser = 6/0.5 = 12 Tread = 10″ = 0.8 feet. Number of treads = (Numbers of risers -1) = 12 – 1 Thickness of waist slab = 6″ = 0.5 feet Length of step = 5 feet VOLUME OF CONCRETE FOR STEPS: Volume of one step = 1/2 x riser x tread x length of step = 1/2 x 0.5 x 0.8 x 5 = 1.03 = 1 cubic feet. As we have 11 number of steps in a flight the volume of steps for first flight = 11 x 1 = 11 cubic feet. CONCRETE VOLUME FOR WAIST SLAB:
  • 55. 55 | P a g e SAQIB IMRAN 0341-7549889 55 To calculate the volume of concrete for waist slab we need to know the inclined length of the waist slab. Horizontal length of waist slab = Tread x Number of steps =0.8333′ x 11 = 9.2 feet. The height of the top of the landing from floor = Number of riser x Height of riser = 12 x 0.5 = 6 feet. The volume of concrete for waist slab = Inclined length of waist slab x Width of waist slab x Thickness of waist slab = 11′ x 5′ x 0.5′ = 27.5 cubic feet ∴ Volume of concrete for first flight = Volume of waist slab + Volume of steps = 27.5+11 = 38.5 cubic feet VOLUME OF CONCRETE FOR LANDING OF STAIRCASE: Length of landing = 10.5 feet Width of landing = 5 feet Thickness of landing = 0.5 feet ∴ Concrete volume for landing = 10.5′ x 5′ x 0.5′ = 26 cubic feet. CONCRETE VOLUME FOR 2ND FLIGHT OF THE STAIRCASE: As the 1st light and 2nd flight are same in our staircase so the volume of concrete will be same. Concrete volume for 2nd flight of the staircase = 38.5 cubic feet. ∴ Total volume of concrete for staircase = Volume of first flight + Volume of second flight + Volume of landing = 38.5 + 38.5 + 26 = 103 cubic feet. Well, this is the wet volume of concrete. To convert wet volume into dry volume we need to multiply with 1.54 ∴ Dry volume of concrete = 103 x 1.54 = 159 cubic feet. QUANTITY OF MATERIALS FOR STAIRCASE: We will calculate for 1:2:4 Concrete mix.
  • 56. 56 | P a g e SAQIB IMRAN 0341-7549889 56 1. Volume of cement = 1/7 x Dry volume = 1/7 x 159 = 22.66 cubic feet. ∴ Number of Cement bags = volume of cement / Volume of cement bag = 22.66 / 1.25 = 18 No’s of bag. (The volume of one bag cement of 50 kg = 1.25 cubic feet) 2. Volume of Sand = 2/7 x Dry volume = 2/7 x 159 = 45 cubic feet. 3. Volume of Aggregate = 4/7 x Dry volume = 4/7 x 159 = 91 cubic feet. Note: Here I have used cubic feet unit and 1:2:4 mix ratio, you can use cubic meter unit and any other mix ratio of concrete. WHAT IS 1.54 IN CONCRETE CALCULATION? In concrete calculation, we always multiply Wet volume with 1.54 to get dry volume. But do you know what is 1.54 or where this 1.54 came from? If You don’t know, no problem. In this article, I will explain what is 1.54 while calculating quantity of cement, sand, aggregates for concrete. let us take a concrete cube. The length of the concrete cube = 1 m The width of the concrete cube = 1 m The height of the concrete cube = 1 m Volume of concrete cube = length x Width x Height = 1 x 1 x 1 = 1 m³ (Wet volume) When we convert this we volume into dry volume, the volume is increased by 54% of wet volume. ∴ Dry volume = Wet volume + 54% of Wet volume = 1 + (54/100) x 1 =1 + 0.54 = 1.54 To convert wet volume of 1 m³ concrete into dry volume = 1.54 To convert wet volume of “n” m³ concrete into dry volume = 1.54 x n
  • 57. 57 | P a g e SAQIB IMRAN 0341-7549889 57 Where n = Wet volume of concrete. Example: The length of the concrete cube = 4 m The width of the concrete cube = 3 m The height of the concrete cube = 2 m Wet volume = 4 x 3 x 2 = 24 m³ ∴ Dry volume = ( Wet volume + 54% of wet volume) = 24 + {(54/100) x 24} = 36.96 m³ Note: Always remember in concrete calculation, we get wet volume first, to convert wet volume into dry volume, multiply wet volume with 1.54. HOW TO CALCULATE RECTANGULAR WATER TANK SIZE AND CAPACITY For high rise building, the dimension of water tank along with drawings are provided from architect office. But for small residential building, we need to calculate by itself. In this article, we will discuss how to calculate rectangular water tank size and capacity. VOLUME OF WATER REQUIREMENT: As per IS code, a person needs 135 litres water per day for daily use. Drinking – 5 Litre
  • 58. 58 | P a g e SAQIB IMRAN 0341-7549889 58 Cooking – 5 litres Bathing and Toilet – 85 litres Washing clothes and Utensils – 30 litres House Cleaning – 10 litres CALCULATION OF TANK SIZE AND CAPACITY: We will calculate for a typical family having 4 members. Total water requirement = 135 x 4 = 540 litres To calculate the size of water tank we must know any one of the following: Length or width or depth of the tank. From the formula of volume of water 1 m3 = 1000 litres 1 litre = 0.001 m3 We are requiring 540 litre water ∴ 540 litres = 0.54 m3 Let us assume the depth of water tank is 0.6 m. ∴ Area of tank = 0.54/0.6 = 0.9 m2 L x B = 0.9 m2 Now if you know the length or breadth you can put the value on the above formula. otherwise, take the length as 2 times of B. ∴ L = 2B 2B x B = 0.9 m2 B2 = 0.45 B = 0.67 ∴ L = 2 x 0.67 = 1.34 m So For 540 litre water tank size Length (L) = 1.34 m Breatdh (B) = 0.67 m Depth (D) = 0.6 m
  • 59. 59 | P a g e SAQIB IMRAN 0341-7549889 59 SEPTIC TANK SHAPE, SIZE & DIMENSIONS WITH TABLE SEPTIC TANK SHAPE, SIZE & DIMENSIONS: Septic tank is a devise which deals with the sewage from water closets. In other words, it is a watertight single-storeyed, underground tank in which sewage is retained sufficiently long to permit sedimentation of suspended solids and practical digestion of settled sludge by anaerobic bacterial action. SHAPE OF SEPTIC TANK:
  • 60. 60 | P a g e SAQIB IMRAN 0341-7549889 60 The simplest form of a septic form is a single compartment, rectangular or cylindrical in shape. The shape of septic tank influences the flow speed of wastewater and sludge accumulation. The dimension of the septic tank should not be too deeper too shallow. Because it can cause short-circuiting of the inlet and outlet flow. Septic tank having a greater surface area with sufficient depth should always be preferred. Rectangular shaped single compartment tank (with length three times of its width) is more favorable. In some cases, cylindrical shape with suitable size is also sound to be a better choice. SEPTIC TANK SIZES, DIMENSIONS & WEIGHTS: SEPTIC TANK SIZE DIMENSIONS WEIGHT (LBS) ANCHOR WEIGHT (LBS) SOIL COVER (IN) 5000 gal 204″L x 96″W x93″H 41,400 30,850 24 3000 gal 165″L x 92″W x 76″H 20,300 23,320 23 2600 gal 147″L x 90″W x 73″H 18,100 20,625 24 2000 gal 162″L x 78″W x 64″H 16,100 15,675 19 1600 gal 145″L x 78″W x 61″H 14,000 11,270 16 1200 gal 111″L x 78″W x 61″H 11,400 9,532 17 1000 gal Low Profile 120″L x 67″W x 57″H 9,500 8,705 17 1000 gal Heavy Duty 96″L x 78″W x 61″H 9,200 8,945 18 800 gal 96″L x 67″W x 57″H 8,000 6,560 16
  • 61. 61 | P a g e SAQIB IMRAN 0341-7549889 61 600 gal 78″L x 56″W x 60″H 6,600 3,810 14 1600/1400 gal 174″L x 90″W x 73″H 23,000 22,410 22 1250/750 gal 162″L x 78″W x 64″H 16,400 15,725 19 1000/600 gal 145″L x 78″W x 61″H 14,700 12,705 17 DESIGN CRITERIA OF SEPTIC TANK SEPTIC TANK: Septic tank is a tank where sewage is kept a long time for sedimentation of suspended solid by anaerobic microorganism activity. Septic Tank Design Basically, the tank is rectangular in shape consisting of rooftop with two chambers, isolated from each other by a baffle wall. The first chamber is called grit chamber in which the sewage enters first and the rest one is called anaerobic chamber. Inlet and outlet pipe should be fitted in such a manner that while entering or existing there should not be any unsettled influence in the sewage of anaerobic chamber. Sand, grit etc is settled down in the grit chamber before the sewage is directed to the anaerobic chamber. In the anaerobic chamber, natural solids settle at the base of the tank where anaerobic bacteria follows up on it and changes over complex unsteady mixes to more straightforward stable mixes. SEPTIC TANK DESIGN: The following measure should be kept in view to design a septic tank: 1. The floor zone of the git chamber must be adequate to decrease the speed of steam and to allow sedimentation. 2. The capacity of a septic tank should be sufficient to give a detainment period fluctuating from 12 hours to 3 days, 24 hours time frame is normally viewed as satisfactory.
  • 62. 62 | P a g e SAQIB IMRAN 0341-7549889 62 3. The depth beneath segment divider opening should be adequate to allow aggregation for the predetermined period. A minimum area of 0.07 m2 for each client in grit chamber and minimum volumetric substance of the grit chamber of 0.02 m3 for every client is required. 4. The minimum width and depth of a septic tank should be 0.75 m and 1 meter underneath water level. The length should be 2 to 4 times of the width. The minimum capacity of a septic tank is granted 1 m3. 5. Every septic tank should be furnished with a ventilating channel minimum diameter of 5 cm. HOW TO CALCULATE VOLUME OF CONCRETE, SHUTTERING AREA & BITUMEN PAINT AREA FOR PLAIN FOOTING In this article I will discuss how to calculate the volume of concrete, shuttering area and bitumen paint area for plain footing (Square footing & Rectangular footing). A. SQUARE FOOTING: Given, Length of footing = 0.5 m Breadth of footing = 0.5 m Depth of footing = 0.25 m Size of column = 0.2 x 0.1 1. Volume of concrete = Area of sq. footing x Depth of sq footing Area of sq. footing = L x B = 0.5 x 0.5 = 0.25 m² Volume of concrete = 0.25 x 0.25 = 0.0625 m³. 2. Shuttering area = 2 (L + B) x D = 2 (0.5+0.5) x 0.25
  • 63. 63 | P a g e SAQIB IMRAN 0341-7549889 63 = 0.5m² 3. Bitumen paint area = Shuttering area + (Top area of footing – column area) = 0.5 + [(0.5 x0.5) -(0.2 x 0.1)] =0.5 + [0.25 – 0.2)] = 0.73 m². 2. RECTANGULAR FOOTING: Given, Length of footing = 1 m Breadth of footing = 0.7 m Depth of footing = 0.25 m Size of column = 0.4 x 0.3 1. Volume of concrete = Area of sq. footing x Depth of sq footing Area of sq. footing = L x B = 1 x 0.7 = 0.7 m² Volume of concrete = 0.7 x 0.25 = 0.175 m³. 2. Shuttering area = 2 (L + B) x D = 2 (1+0.7) x 0.25 = 0.85m² 3. Bitumen paint area = Shuttering area + (Top area of footing – column area) = 0.85 + [(1 x0.7) -(0.4 x 0.3)] =0.85 + [0.7 – 0.12)] = 1.43 m². HOW TO CALCULATE CEMENT, SAND QUANTITY FOR PLASTERING? Following points should be remembered while calculating the quantity of cement, sand for plastering work.
  • 64. 64 | P a g e SAQIB IMRAN 0341-7549889 64 1. For wall plastering, Cement : Sand = 1 : 6 2. For ceiling plastering, Cement : Sand = 1 : 4 3. Thickness of plaster should be in between 12-15 mm. If an additional coat is required then do not do it at one go. 4. Use good quality of cement & Sand. 5. Use measuring box (not head pan) for site mix. We will calculate cement and sand for 100 m2 plastering area in 1:6 ratio and thickness of 12 mm. Cement Mortar Required: Plastering thickness = 12 mm = 12/1000 = 0.012m Volume of cement mortar required = ( Plastering Area x thickness ) = 100 m2 x 0.012m = 1.2 m3 (This is wet volume of cement mortar (after mixing water) but we need dry volume. To get dry volume consider 35% bulking of sand and 20% wastages = 1.2 m3 x (1+0.2+0.35) (Rather than 35% sand bulkage and 20% wastage you can add 1.54 as constant) = 1.86 m3 Cement : Sand = 1 : 6 Sum of ratio =( 1 + 6) = 7 ∴ Cement required = 1.86 x 1/7 = 0.265 m3 = 0.265/0.0347 ( 0.0347 m3 = 1 bag = 50 kg cement) = 7.66 bags (≈ 8 Bags) ∴ Sand required = 1.86 x 6/7 = 1.59 m3 Here we have calculated in Sq.m but you can also calculate it in Sq.ft. HOW TO CALCULATE QUANTITY OF PAINT FOR BUILDING: Painting is one of the most essential steps to be done after construction of any building/house. Painting is done to protect the surface of the walls as well as to increase appearance. In this article, I will discuss how to calculate the quantity of paint required in a building. Before starting the calculation let me tell you one important thing that quantity of paint is calculated in gallon. There are two types of gallons US gallon and Uk gallon.
  • 65. 65 | P a g e SAQIB IMRAN 0341-7549889 65 1 US gallon = 3.785 litres 1 Uk gallon = 4.546 litres. In this calculation we will use US gallon. Let the length of the wall = 15 feet The height of the wall = 12 feet. Area of the wall 15 x 12 = 180 sft. THUMB RULE FOR PAINT CALCULATION: Generally, 1 gallon of paint can cover up to 350 sft area of wet wall and 1 gallon of paint can cover up to 200 sft area of dry wall. PAINT QUANTITY OF WET WALL: Area of wet wall =180 sft Paint covered area = 300 sft Quantity of paint = 180/350 = 0.514 litre. Let the price of 1 gallon paint = Rs 1200. Price of 0.514 gallon paint = 0.514 x 1200 = 617 Rs. PAINT QUANTITY OF DRY WALL: Area of dry wall = 180 sft. Pain covered area = 200 Quantity of paint = 180/200 =0.9 gallon. Price of 0.9 gallon paint = 0.9 x 1200 = 1080 Rs. Note: 1. If the wall has any openings, subtract the area of openings from total area & then calculate paint quantity.
  • 66. 66 | P a g e SAQIB IMRAN 0341-7549889 66 HOW TO CALCULATE SHUTTERING OILAND ITS PRICE Shuttering oil is very useful material required for every construction projects. So it is very important to know the shuttering oil quantity. In this article, I will discuss how to calculate shuttering oil and its price. Before starting the calculation let me tell you first what is shuttering oil and why we use it in shuttering/formwork. WHAT IS SHUTTERING OIL? Shuttering oil are high quality mineral oil which is used on the shuttering plates/mould for easy removal of shuttering. WHY WE USE SHUTTERING OIL IN FORMWORK? The main purposes of using shuttering oil are as follows: 1. Shuttering oil works as a releasing agent between shuttering plates and concrete. It helps easy removal of shuttering at the time of deshuttering. 2. It gives a good and better finish after deshuttering. 3. It keeps the shuttering plates and mould in good condition and ensures repetitive use in more projects. HOW TO CALCULATE SHUTTERING OIL & ITS PRICE: Let us calculate the quantity of shuttering oil for the above slab. Length of slab = 12 m Breadth of slab = 10 m Area of slab = L x B = 12x 10 = 120 m² There are two types of shuttering plates used in construction. 1. WOOD SHUTTERING: Generally, 1 liter shuttering oil covers upto 30 to 40 m² area in wood shuttering.
  • 67. 67 | P a g e SAQIB IMRAN 0341-7549889 67 The quantity of shuttering oil = Total area/1 liter covering area = 120/30 = 4 litre Price: Let the price of 1 liter shuttering oil = Rs. 250. The price of 4 liter shuttering oil = 250 x 4 = Rs. 1000. 2. STEEL SHUTTERING: Generally, 1 liter shuttering oil covers upto 60 to 70 m² area in steel shuttering. The quantity of shuttering oil = Total area/1 liter covering area = 120/60 = 2 litre Price: Let the price of 1 liter shuttering oil is Rs. 250. The price of 2 liter shuttering oil = 250 x 2 = Rs. 500. HOW TO CALCULATE CONCRETE VOLUME FOR RETAINING WALL: Retaining wall is a masonry wall constructed to resist the pressure of liquid, earth filling, sand or other granular material filled behind it. In this article, I will discuss how to calculate the concrete volume for retaining wall. Let’s get started. EXAMPLE 1: To calculate the volume of retaining wall we need to calculate the volume of retaining wall. Here I have divided the retaining wall into two parts, part A is the base slab and part B is the stem of retaining wall. So Volume of retaining wall = Volume of base slab + Volume of stem. Volume of base slab = l x b x h = 10 x 3 x 0.2 = 6 m³
  • 68. 68 | P a g e SAQIB IMRAN 0341-7549889 68 The stem is a trapezoid. So Volume of stem = [{(a + b)/2} x h] x l = [{(0.5 + 0.2)/2} x 3] x 10 = 21 m³ The total volume of retaining wall = 6 + 21 = 27 m³ So the volume of concrete for the retaining wall = 27 m³ Let’s take another example: EXAMPLE 2: Here I have divided the retaining wall into three parts, part A is the base slab, part B is the stem and part C is the counterfort of the retaining wall. The volume of retaining wall = Volume of base slab + Volume of stem + Volume of counterfort = Volume of A + Volume of B + Volume of C Volume of A = l x b x h = 12 x 2.5 x 0.2 = 6 m³ Part B is a trapezooid. So Volume of B = [{(a + b)/2} x h] x l = [{(0.2 + 0.3)/2} x 3] x 12 = 9 m³ As part C is also a trapezoid So Volume of C = [{(a + b)/2} x h] x l = [{(0.5 + 2)/2} x 3] x 0.2 = 0.75 m³ In the above retaining wall there is 2 counterfort so Volume of C = 0.75 x 2 = 1.5 m³ The total volume of retaining wall = 6 + 9 + 1.5 = 16.5 m³.
  • 69. 69 | P a g e SAQIB IMRAN 0341-7549889 69 HOW TO CALCULATE NUMBER OF TILES IN A ROOM: Calculation of tiles needed for floors and walls is so simple and easy. in this post, I will discuss how to calculate no. of tiles required in a room. So let’s start. STEP 1- CALCULATE AREA OF THE FLOOR: let the length of the floor = 14 feet. Breadth of the floor = 12 feet. ∴ Area of floor = length of floor x breadth of floor = 14 x 12 = 168 sft. STEP 2 – CALCULATE AREA OF 1 TILE: There are different tile sizes such as 20cmx20cm, 30cmx30cm, 45×45, 60cmx60cm etc. In this calculattion we will use 60×60 cm tiles. Length of 1 tile = 60 cm Breadth of 1 tile = 60 cm. ∴ Area of 1 tile = 60 x 60 = 3600 cm² = 3.6 sft. STEP 3 – DIVIDE FLOOR AREA BY AREA OF 1 TILE: ∴ No. of tiles required = Area of floor/ area of 1 tile = 168/3.6 = 46.6 ≈ 47. ∴ 47 tiles are required for the above floor. Note: Consider 5% wastages. Similarly, you can also calculate tiles needed for walls.
  • 70. 70 | P a g e SAQIB IMRAN 0341-7549889 70 HOW TO CALCULATE LAND AREA OR PLOT AREA: Sometimes we may need to know the area of any land or plot for various reasons such as buying, selling of land, or constructing house/building etc. In this article, I will explain how to calculate land are or plot area for a site. Area Formula For Different Shapes: But for complex shaped land you cannot easily calculate the area. In that case, we use HERON’s Formula which is given below:
  • 71. 71 | P a g e SAQIB IMRAN 0341-7549889 71 Where S = Perimeter of the triangle S = (a + b + c)/2 a = Distance of AB b = Distance of BC c = Distance of AC Let’s take an example, First of all, divide the land area into minimum possible no. of triangle. Then measure all the required distance (like AB, AC, AE etc) by using a tape or chain. 1. FOR △ ACD:
  • 72. 72 | P a g e SAQIB IMRAN 0341-7549889 72 AC = 10 feet. CD = 12 feet. AD = 14 feet. S = (a + b + c)/2 = (10 + 12 + 14)/2 = 18 feet. 2. FOR △AED: AD = 14 feet. AE = 14feet. DE = 12 feet. S = (a + b + c)/2 = (14+14+12)/2 = 20 feet. 3. FOR △AEB: AB = 16 feet. BE = 12 feet. AE = 12 feet. S = (a + b + c)/2 = (16 + 12 + 12)/2 = 20 feet.
  • 73. 73 | P a g e SAQIB IMRAN 0341-7549889 73 Total Area Of Land = 58.78 + 75.89 + 71.55 = 206.22 ft² NOTE: This method does not give appropriate result for curve shaped area, for curve shaped area we need to use difinite integral method. CENTER LINE METHOD OF ESTIMATION: There are three different methods of estimation. 1. Center line method. 2. Long and short wall method. 3. Crossing method. In this article, I will discuss center line method briefly for the estimation of materials. WHAT IS CENTER LINE METHOD: In this method of estimation, the total center line length of walls in a building is first calculated, then the center line length is multiplied with the breadth and depth of respective item to get the total quantity at a time. The center line length for different sections of walls in a building shall be worked out separately. For verandah walls or partition walls joining the main walls, the center line length shall be reduced by half of the breadth of the layer of main wall that joins with the partition or verandah wall at the same level. The number of such joints is studied first to obtain the center line length. By using this method estimation can be finished more quickly. This method is as accurate as other methods (except unsymmetrical wall). This method is suitably used for estimating circular, rectangular, hexagonal, octagonal etc shaped building. Let us take an example: FOR ONE ROOM BUILDING:
  • 74. 74 | P a g e SAQIB IMRAN 0341-7549889 74 First we need to calculate total center line length of the building. Total center line length = 2 x 5.3 + 2 x 4.3 = 19.2 m. 1. Earthwork in excavation = Total center line length x breadth x depth = 19.2 x 0.9 x (0.3+0.3+0.3) = 19.2 x 0.9 x 0.9 = 15.52 cu.m 2. Concrete in foundation = 19.2 x 0.9 x 0.3 = 5.18 cu.m 3. a) Brickwork in foundation for 1st footing = 19.2 x 0.6 x 0.3 cu.m b) Brickwork in foundation for 2nd footing = 19.2 x 0.5 x 0.3 = 2.88 cu.m 4. Brickwork in superstructure = 19.2 x 3.5 x 0.3 = 20.16 cu.m FOR TWO ROOM BUILDING:
  • 75. 75 | P a g e SAQIB IMRAN 0341-7549889 75 Total center line length = 2 x (5.3+5.3) + 3 x 4.3 = 34.1 m. 1. Earthwork in excavation = Total center line length x breadth x depth = 34.1 x 0.9 x (0.3+0.3+0.3) = 34.1 x 0.9 x 0.9 = 27.62 cu.m 2. Concrete in foundation = 34.1 x 0.9 x 0.3 = 9.20 cu.m 3. a) Brickwork in foundation for 1st footing = 34.1 x 0.6 x 0.3 = 6.13 cu.m b) Brickwork in foundation for 2nd footing = 34.1 x 0.5 x 0.3 = 5.11 cu.m 4. Brickwork in superstructure = 34.1 x 3.5 x 0.3 = 35.8 cu.m Thus you can estimate quantity of different items such as Quantity of D.P.C = Total Centre line length x Breadth of foundation x Thickness of D.P.C Quantity of plinth beam = Total Centre line length x Breadth of the beam x Depth of beam. Quantity of wall plaster for 2 sides = Total centre line length x Height of wall x Thickness of plaster. Quantity of Paint for 2 sides of wall = Total centre line length x Height of wall x 2 = Area of paint in sq.ft ONE WAY SLAB DESIGN – HOW TO DESIGN ONE WAY SLAB In this article, I will discuss how to design One way slab with example. WHAT IS ONE WAY SLAB?
  • 76. 76 | P a g e SAQIB IMRAN 0341-7549889 76 When a slab is supported on all four sides and the ratio of long span to short span is equal or greater than two, it will be considered as one way slab. The load on the slab is carried by the short span in one direction. However main reinforcement bar and distribution bar in transverse direction. Longer span (l)/Shorter span (b) ≥ 2 ACI CODE SPECIFICATIONS FOR ONE WAY SLAB DESIGN: 1. MINIMUM SLAB THICKNESS: To control deflection, ACI Code 9.5.2.1 specifies minimum thickness values for one-way solid slabs. 2. SPAN: According to ACI code 8.7.1 If the slab rests freely on its supports, the span length may be taken as equal to the clear span plus the depth of the slab but need not exceed the distance between centers of supports. 3. BAR SPACING: The lateral spacing of the flexural bars should not exceed 3 times the thickness h or 18 inch according to ACI code 7.6.5 The lateral spacing of temperature and shrinkage reinforcement should not be placed farther apart than 5 times the slab thickness or 18 inch according to ACI code 7.12.2 4. MAXIMUM REINFORCEMENT RATIO: Reinforcement ratio is the ratio of reinforcement area to gross concrete area based on total depth of slab. One-way solid slabs are designed as rectangular sections subjected to shear and moment. Thus, the maximum reinforcement ratio corresponds to a net tensile strain in the reinforcement, €t of 0.004 5. MINIMUM REINFORCEMENT RATIO: A) FOR TEMPERATURE AND SHRINKAGE REINFORCEMENT : According to ACI Code 7.12.2.1 Slabs with Grade 40 or 50 deformed bars –> 0.0020 Slabs with Grade 60 deformed bars –> 0.0018 Slabs where reinforcement with yield strength Exceeding 60000 psi- ->( 0.0018 x 60000/fy) B) FOR FLEXURAL REINFORCEMENT : According to ACI Code 10.5.4, the minimum flexural reinforcement is not to be less than the shrinkage reinforcement, or 0.0018 EXAMPLE PROBLEM:
  • 77. 77 | P a g e SAQIB IMRAN 0341-7549889 77 A reinforced concrete slab is built integrally with its supports and consists of equal span of 15 ft. The service live load is 100 psf and 4000 psi concrete is specified for use with steel with a yield stress equal to 60000 psi. Design the slab following the provisions of the ACI code. THICKNESS ESTIMATION: For being both ends continuous minimum slab thickness = L/28 =(15 x 120)/28= 6.43 in. Let a trial thickness of 6.50 in. LOAD CALCULATION: Consider only a 1 ft width of beam. Dead load = 150 x (6.50/12)) = 81 psf Live load = 100 psf Factored DL and LL ={81+1.2+(100 x 1.6)} =257 psf DETERMINE MAXIMUM MOMENTS: Factored moments at critical sections by ACI code : At interior support : -M=1/9 x 0.257 x 152 = 6.43 k-ft At midspan : +M=1/14 x 0.257 x 152 = 4.13 k-ft At exterior support : -M=1/24 x 0.257 x 152 = 2.41 k-ft Mmax = 6.43 k-ft =0.85 x 0.85 x 4/60 x 0.003/(0.003+0.004) = 0.021
  • 78. 78 | P a g e SAQIB IMRAN 0341-7549889 78 Now, = 2.64 in CHECK FOR AVAILABILITY OF THICKNESS: As ‘d’ is less than the effective depth of (6.50-1.00) = 5.50 in, the thickness of 6.50 in can be adopted. REINFORCEMENT CALCULATION: Let, a = 1 inch At interior support: Checking the assumed depth of a by Similarly at Midspan: As = (4.13 x 12)/(0.90 x 60 x 5.29) = 0.17 in² At Exterior support: As = (2.41 x 12)/(0.90 x 60 x 5.29) = 0.10 in² MINIMUM REINFORCEMENT: As = 0.0018 x 12 x 6.50 = 0.14 in² So we have to provide this amount of reinforcement where As is less than 0.14 in². SHRINKAGE REINFORCEMENT: Minimum reinforcement for shrinkage and temperature is As = 0.0018 x 12 x 6.50 = 0.14 in² FINAL DESIGN:
  • 79. 79 | P a g e SAQIB IMRAN 0341-7549889 79 LAYOUT OF ONE WAY SLAB:
  • 80. 80 | P a g e SAQIB IMRAN 0341-7549889 80 DESIGN OF COLUMNS AS PER ACI: 1. Maximum and Minimum Reinforcement Ratio: The minimum reinforcement ratio of 1 % is to be used in tied or spirally reinforced columns. This minimum reinforcement is needed to safeguard against any bending, reduce the effect of shrinkage and creep and enhance ductility of columns. 2. Minimum Number of Reinforcing Bars: Minimum four bars within rectangular or circular sections; or one bar in each corner of the cross section for other shapes and a minimum of six bars in spirally reinforced columns should be used. 3. Clear Distance between Reinforcing Bars: For tied or spirally reinforced columns, clear distance between bars should not be less than the larger of 150 times bar diameter or 4 cm. 4. Concrete Protection Cover: The clear concrete cover should not be less than 4 cm for columns not exposed to weather or in contact with ground. It is essential for protecting the reinforcement from corrosion or fire hazards. 5. Minimum Cross-Sectional Dimensions: For practical considerations, column dimensions can be taken as multiples of 5 cm.
  • 81. 81 | P a g e SAQIB IMRAN 0341-7549889 81 6. Lateral Reinforcement: Ties are effective in restraining the longitudinal bars from buckling out through the surface of the column, holding the reinforcement cage together during the construction process, confining the concrete core and when columns are subjected to horizontal forces, they serve as shear reinforcement. Spirals, on the other hand, serve in addition to these benefits in compensating for the strength loss due to spalling of the outside concrete shell at ultimate column strength. 7. Ties: For longitudinal bars, 32 mm or smaller, lateral ties 10 mm in diameter should be used. In our country and in some neighboring countries, ties of 8 mm dia are used for column construction CALCULATION OF EARTH PRESSURE: The thrust due to the back filling, which may be assumed to be earth, is generally calculated by Rankine’s theory. The theory is based on the assumption that the backing material or earth consists of cohesionless granular particles. The formulae derived from this theory under different conditions of backfilling are given below: Case 1: Walls with earth levelled with the top of the wall: a) Horizontal pressure per sq.m (ph) at a depth of (h) meter below the levelled top is given by the following formula: Where w = Weight of filling in kg/m3 ϕ = Angle of repose of the soil. b) Total horizontal pressure (P) at a depth of (h) meter per meter length of the wall is given by the following formula: Acting at h/3 meter from the base. Case 2: In case of submerged retaining wall or wall retaining earth filled at slope of a° to the horizontal, the formula giving lateral earth pressure (ph) is given by:
  • 82. 82 | P a g e SAQIB IMRAN 0341-7549889 82 Acting parallel to the surcharge slope of the filling. Total pressure (P) at depth h meter per meter length of the wall is given by the formula:
  • 83. 83 | P a g e SAQIB IMRAN 0341-7549889 83 How to calculate quantity of mortar and its materials Below is the step by step process of calculating quantity of mortar required for cementing.  Area of the surface multiply with the thickness gives the quantity of mortar for uniform thickness.  This quantity is increased by 30% for filling the joints and to make up uniform surface of wall. It will give wet mixed mortar.  This mortar quantity is further increased by 25% to get the dry volume of the ingredients.  Quantity of each material of the mortar may be found by dividing the dry volume of mortar by the sum of numerals of the proportions and multiplying the answer with the individual numeral. For example Materials for 12 mm or half inch thick plastering in wall for 100 square meter  First of all, we have to multiply 100 square meter surface with 12 mm.  100 square meter x 0.012 m = 1.2 cubic meter. (12 mm can also be written as 0.012)  1.2 cubic meter is wet mixed mortar for uniform thickness.  Add 30% in this value to fill up joints, uneven surfaces, etc., the quantity of mortar comes out 1.2 + 0.36 = 1.56 cubic meter.  Increasing by 25% the total dry volume will be 1.2+0.36+0.39 = 1.95 cubic meter or 2 cubic meter.  For cement sand mortar, cement = dry volume / ( sum of ratios) x numeral of cement.  For 1:4 cement sand mortar, cement will be 2/5 x 1 = 0.4 cubic meter.  For 1:4 cement sand mortar, sand will be 2/5 x 4 = 1.6 cubic meter.  In this way you can calculate the dry volume of any ratio of mortar ingredients. Measurement of Plinth Area and Carpet Area of a Building Plinth area and carpet area of a building is measured for estimation and calculation of building cost. It is also a measure of usable space of building.
  • 84. 84 | P a g e SAQIB IMRAN 0341-7549889 84 Plinth area is the covered built-up area measured at the floor level of any storey or at the floor level of the basement. Plinth area is also called as built-up area and is the entire area occupied by the building including internal and external walls. Plinth area is generally 10-20% more than carpet area. Fig.1: Plinth Area of a Room in Building Carpet area the covered area of the usable spaces of rooms at any floor. It is measured between walls to walls within the building and is the sum of the actual areas of the rooms where you can carpet. Fig.1: Carpet Area of a Room in Building Measurement of Plinth Area and Carpet Area of a Building
  • 85. 85 | P a g e SAQIB IMRAN 0341-7549889 85 For measurement, the lengths and widths should be measured nearest to 0.01m and areas should be rounded to 0.01 m2. In Case of feet system, length should be measured to nearest 1 inch. During the measurement, following categories are measured separately: Basement Floor without cladding (stilled floor) Floors including top floor which may be partly covered Garage Mezzanine floor Measurement of Plinth Area Following areas are included during measurement of plinth area: 1. Area of the wall at the floor level, excluding plinth offsets. If there are any common walls between two buildings, half of the area of such walls shall be considered in the plinth area. When building consists of columns projecting beyond the cladding, the plinth area is measured upto the external face of the cladding (in case of corrugated sheet, cladding outer edge of the corrugation is considered). 2. Areas of the internal shaft for sanitary installations and garbage chute, electrical, telecom and firefighting services provided these do not exceed 2 m2 in area. 3. Vertical duct for air conditioning and lift well including landing. 4. Staircase room or head room other than terrace level 5. Machine room 6. Porch 7. Open projections of veranda, balconies and parapets, if the area is protected by projections, full area is included in plinth area, if the area is un-protected by projections, 50% of the area is included. 8. Recess by cantilevering beyond external walls, bay window is the best example. If the recess height is up to 1.0 meter, 25% of such area shall be included. If the recess height is 1.0 to 2.0 meters, 50% of such area shall be included. If the recess height is above 2.0 meters, 100% of such area shall be included. The following is not to be included in the calculation of plinth area: 1. Additional floor for seating in assembly buildings, theatres, auditoriums 2. Cantilevered porch 3. Balcony 4. Area of loft 5. Internal sanitary shaft and garbage chute, provided these are more than 2 m2 in area 6. Area of architectural band, cornice, etc. 7. Area of vertical sun breaker or box louver projecting out and other architectural features such as slab projection for keeping flower pots 8. Open platform 9. Terrace at first floor
  • 86. 86 | P a g e SAQIB IMRAN 0341-7549889 86 10. Spiral staircase including landing 11. Towers, turrets, domes projecting above the terrace level at terrace. Wall Area in Plinth Area Calculation Wall area is also included in plinth area calculation. Wall area is the area on plan occupied by walls on any particular floor. It includes the thickness of any finishing or dado tiles if the height of such wall is more than 1m from floor finish. Following should be included in wall area of the building: 1. Area on plan occupied by doors and other openings 2. Intermediate pillars, supports and other such obstructions within the plinth area irrespective of their locations 3. Pilasters along wall if exceeding 300 cm2 in area 4. Flues within the wall 5. Built-in cupboards, wardrobes, shelves appearing within a height of 2.2m from floor 6. Fire place projecting beyond the face of wall in living or bed room The following is not included in wall area: 1. Pilaster along wall not exceeding 300 cm2 in are 2. Platforms projecting beyond the face of the wall Measurement of the Carpet Area of the Building Carpet area is the plinth area less the area of the following portions of the building: 1. Wall area 2. Veranda 3. Corridor and passage 4. Entrance hall and porch 5. Staircase and stair cover 6. Lift shaft and machine room for lift 7. Bathroom and lavatory 8. Kitchen and pantry 9. Store 10. Canteen 11. Air conditioning duct and plant room 12. Shaft for sanitary piping 13. Stilted floor and garage