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Concrete technology

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Concrete is a widely used construction material consisting of cement, water, and aggregates. The strength of concrete is specified using its 28-day cube strength in N/sq.mm. Formwork is used to mold wet concrete into desired shapes and allow it to cure. Formwork design involves choosing traditional or systematic approaches using wood or steel components like props, beams, sheathing to form columns, walls, and beams until the concrete gains sufficient strength. Proper formwork is important for quality concrete finish and structural integrity.

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Concrete • One of the very important and widely used material in construction • The Grade of the concrete is specified by its 28 day’s cube strength (E.g. M20 means the cube strength is 20 N/sq.mm) • Concrete used on works is specified according to IS 456 (2000). 1
•Consists of Portland cement, water, and aggregate ( Fine& Coarse ) •Cement, water and fine aggregate – mortar -Admixtures added for specific purposes like – Entrain numerous microscopic air bubbles – Retard the initial set of the concrete – Waterproof the concrete , etc. 2
Concrete chain Cement supply sand supply Coarse aggregate Water supply supply Transporting, unloading and stacking Gauging Mixing Slump test Cube test Transporting Placing 3 Compaction Curing
PROPORTIONING CONCRETE MIXTURES • For successful utilization, the mixtures must be properly proportioned ( Mix design ) Concrete Mix Design-IS 10262 Designed to achieve a defined • workability • strength • durability 4
BATCHING AND MIXING OF CONCRETE MATERIALS • Batching is weighing or volumetrically measuring and introducing into the mixer the ingredients for a batch of concrete • A batch is the quantity of concrete mixed at one time More accurate to measure by weight • As per IS 4925 : 1968 - specification for concrete batching and mixing 5
Slump test to test workability 6
Cube test to test the strength 7
Formwork system It is a mold used to shape the concrete and support the concrete until it attains sufficient strength to carry its own weight.
Introduction  No desirable structure can be built without the use of formworks.  Such is the importance of formwork that it constitutes 30% of Cost 60% of Time Construction  Apart from that the quality of concrete finish and soundness of concrete depends very much on the formwork system.
Types of Formwork Formwork can be divided into two approaches :  Traditional approach  Systematic approach (System formwork)
Traditional formwork system in System formwork in Progress Progress Collapsible A network of Wooden A network of type props wooden H-beams posts wooden beams (CT props) to support the (ballies) to support the sheathing. sheathing Pictures and sketches taken from L&T- DOKA formwork manuals
Column Formwork Pictures and sketches taken from L&T- DOKA formwork manuals
Wall Formwork Pictures and sketches taken from L&T- DOKA formwork manuals
Beam Forming Support Pictures and sketches taken from L&T- DOKA formwork manuals

More Related Content

Concrete technology

  • 1. Concrete • One of the very important and widely used material in construction • The Grade of the concrete is specified by its 28 day’s cube strength (E.g. M20 means the cube strength is 20 N/sq.mm) • Concrete used on works is specified according to IS 456 (2000). 1
  • 2. •Consists of Portland cement, water, and aggregate ( Fine& Coarse ) •Cement, water and fine aggregate – mortar -Admixtures added for specific purposes like – Entrain numerous microscopic air bubbles – Retard the initial set of the concrete – Waterproof the concrete , etc. 2
  • 3. Concrete chain Cement supply sand supply Coarse aggregate Water supply supply Transporting, unloading and stacking Gauging Mixing Slump test Cube test Transporting Placing 3 Compaction Curing
  • 4. PROPORTIONING CONCRETE MIXTURES • For successful utilization, the mixtures must be properly proportioned ( Mix design ) Concrete Mix Design-IS 10262 Designed to achieve a defined • workability • strength • durability 4
  • 5. BATCHING AND MIXING OF CONCRETE MATERIALS • Batching is weighing or volumetrically measuring and introducing into the mixer the ingredients for a batch of concrete • A batch is the quantity of concrete mixed at one time More accurate to measure by weight • As per IS 4925 : 1968 - specification for concrete batching and mixing 5
  • 6. Slump test to test workability 6
  • 7. Cube test to test the strength 7
  • 8. Formwork system It is a mold used to shape the concrete and support the concrete until it attains sufficient strength to carry its own weight.
  • 9. Introduction  No desirable structure can be built without the use of formworks.  Such is the importance of formwork that it constitutes 30% of Cost 60% of Time Construction  Apart from that the quality of concrete finish and soundness of concrete depends very much on the formwork system.
  • 10. Types of Formwork Formwork can be divided into two approaches :  Traditional approach  Systematic approach (System formwork)
  • 11. Traditional formwork system in System formwork in Progress Progress Collapsible A network of Wooden A network of type props wooden H-beams posts wooden beams (CT props) to support the (ballies) to support the sheathing. sheathing Pictures and sketches taken from L&T- DOKA formwork manuals
  • 12. Column Formwork Pictures and sketches taken from L&T- DOKA formwork manuals
  • 13. Wall Formwork Pictures and sketches taken from L&T- DOKA formwork manuals
  • 14. Beam Forming Support Pictures and sketches taken from L&T- DOKA formwork manuals

Editor's Notes

  1. CE503 Construction Methods & Equipment
  2. CE503 Construction Methods & Equipment
  3. CE503 Construction Methods & Equipment