Cement and GGBS

Concrete is one of the major construction material used in the construction now a day. It is a composite material containing cement, coarse aggregate, fine aggregate and water. In the future, fresh water will be very difficult to get and obtain. It is said that in 2024 half of the mankind will live in the areas where fresh water is not enough. Also, UN and WMO are predicting 5 billion people will be in short of even drinking water. The depletion of natural sand deposits and illegal sand mining is a common issue on these days. Extraction of river sand as fine aggregate affect negatively on river ecosystems, navigation and flood control. This paper presents an experimental critical review of existing studies based on the effects of using sea-sand and/or seawater as raw materials of concrete on the properties of the resulting concrete, short and long term strength as well as durability. It has been shown by some researchers that concrete made with sea water and sea sand develops its early strength faster than that of ordinary concrete, but the former achieves a long term strength similar. Attempts were made to over come the problems of using sea water and sea sand in concrete by adding some suitable material. The samples are from cochin, by the means of laboratory tests to assess the compatibility of modifying the samples. Compressive strength, flexural strength and tensile strength test was conducted on the various concrete specimens with various proportion for the comparison analysis. The effort of improving this technology saves fresh water and river, reduces water scarcity. I. INTRODUCTION In the year of 2016, the amount of cement produced in the world reached 4.20 billion tonnes and the estimated concrete production was around 25 billion tonnes. The production of aggregates (including both coarse and fine aggregate) reached about 40 billion tonnes in the year 2015. The consumption of huge amounts of raw materials, mainly river sand and freshwater, in concrete production has raised very serious environmental issues. The depletion of natural sand deposits and illegal sand mining is a common issue these days. Extraction of river sand as fine aggregate impacts negatively on river ecosystems, navigation and flood control. Similarly, the consumption of a great amount of freshwater poses a great challenge due to water shortage in many parts of the world. Besides sand and water, consumption of the other main constituents of concrete, has also caused major environmental concerns, but the present discussion is mainly concerned with alternative solutions for sand and water. The need of desalted sea sand and sea water cause to extra huge production cost. The direct use of both sea-sand and seawater without desalting in concrete production is particularly implemented for marine and coastal projects, for which the supplies of freshwater and river sand are limited where. Several studies agree that in comparison with concrete mixed with fresh water, concrete mixed with sea water increases early age strength and reduces setting time. The concrete produced with seawater using blast furnace slag cement and a low water cement ratio increases the resistance towards chloride penetration. Sea water can be used instead of fresh water where it is not available such as isolated islands and coastal areas. As a result, the topic of seawater sea sand concrete or sea sand seawater concrete has attracted the attention of us. The purpose of this project is to study about the use of sea-sand and seawater as raw materials for concrete to replace river sand and freshwater. In general, concrete cast with seawater but ordinary fine aggregate is referred to as seawater concrete, while concrete cast with sea-sand but freshwater is referred to as sea sand concrete. The demand for manufactured fine aggregates is increasing highly as river sand cannot meet the rising demand of construction sector. The limited supply capacity of natural sea sand cannot meet the supply guarantee needs. Under this circumstances the manufactured sand is impossible. In many countries sea sand has been used for making cement concrete since long time ago, naturally, its technology depends on the research achievement and specific conditions of each country. Therefore, studying the differences in properties of both river and sea sand will give an idea whether sea sand can be altered in such a way that it can be used as a substitute for the depleting river sand. Removing process of river sand from river bed has environmental impacts. The discussions presented in this report have clearly indicated that sea-sand and seawater structures are most attractive in marine/coastal construction, where steel corrosion is a major concern and access to river sand and freshwater is limited but sea-sand and huge amount of sea water are easily available, mainly in island and costal area where fresh water availability is low.

High Performance Concrete can be considered as a logical development of cement concrete in which the ingredients are proportioned and selected to contribute efficiently to the various properties of cement concrete in fresh as well as in hardened states. Higher strength is one of the features of High Performance Concrete which provides significant structural advantages. The three major components contributing to the cost of a structural member are concrete, steel reinforcement and formwork. This paper aims at comparing these major components when concrete of higher grade is used in the design and to establish that High strength concrete provides the most economical way for designing the load bearing members and to carry a vertical load to the building foundation through columns. The mix design variables affecting the concrete strength which are the most critical in the strength development of concrete includes water-cementitious material ratio, total cementitious material, cement-admixture ratio, amount of super plasticizer dose .These factors are to be analyzed in order to obtain a mix for concrete of higher grade

Supplementary cementitious materials (SCM) are the integral part of modern concrete with significant enhancement in concrete performance. Low cost of production, low heat of hydration along with improved mechanical properties encourage the replacement of ordinary Portland cement (OPC) with SCMs to a greater extent. The study focusses on influence of Ground granulated blast furnace slag (GGBS) as SCM in production of concrete paver blocks. Compressive strength, split tensile strength, and flexural strength are the properties under consideration. Improved compressive strength and flexural strength was observed in blended concrete with 20% and 40% GGBS replacement levels.

The potential applicability of several biopolymers, including xanthan gum, diutan gum, acacia gum, modified starch, guar gum and a cellulosic polymer, for maintaining the solid particles of a particulate grout in suspension has been evaluated through static bleeding tests. The grout material investigated was ground granulated blast-furnace slag (GGBS) cement prepared at different water to binder ratio values ranging from 2:1 to 5:1. Among the biopolymers studied, diutan gum and xanthan gum were found to have the highest performance in bleeding prevention at very low concentrations in ranging 0.25–1.0%. A synergy was observed for xanthan gum and guar gum and for xanthan gum and cellulosic polymer combinations. This helps reduce the overall amount of biopolymer required for suspension stabilization. By measuring the zeta potential and viscosity values of the biopolymer-added grouts, the mechanisms underlying the sedimentation inhibitory action of the biopolymers are discussed.

The use of fibre reinforcement concrete provides the ductility and toughness required for higher strength. The single type of fibre with reinforcement in concrete improves the mechanical properties at certain level. In concrete the different type of pozzolanic materials are normally used to improve the properties. GGBS can be used as partial replacement of cement for better performance and it helps in producing high strength concrete because of the total participation in hardening process. Fibres are generally used to resist cracking and to assist in strengthening of concrete. Adding a steel and sisal fibres to concrete at low volume dosage rates provides benefits not available in conventional concrete. The use of GGBS, steel and sisal fibre improves the shear strength, torsional structural strength, impact strength and enhanced fatigue and crack resistance. This study focuses on the compression, split tensile and flexural strength properties of M20 grade concrete. The fibre reinforced concrete contains different percentage of GGBS used as partial replacement for cement in addition to steel and sisal fibre. The GGBS is added to the concrete with the percentage of 0%, 10%, 20% and 30% by the weight of cement and 0%, 0.5%, 1% and 1.5% of steel and sisal fibre is used. Concrete specimens casted are cubes, cylinders and beams. After completion of curing process the concrete specimens are tested at 28 days and the final test results are recorded, analyzed and discussed. The strength achieved due to the addition of GGBS and fibres is compared with the nominal concrete and also the strength achieved by GGBS with the addition of steel fibres is compared with the sisal FRC.

This study investigates the effect of fly ash (FA) and ground granulated blast furnace slag (GGBS) as partial
replacement of cement in the manufacture of concrete. Manufactured sand (M-sand) is used as fine aggregate in the place of
scarce river sand. The grade of concrete used is M20. The cube, cylindrical and prism specimens were cast and subjected to wet
curing. The compressive strength, split tensile strength and flexural strength of concrete specimen was tested at 28 days. The
experimental results indicated that replacement of cement by flyash resulted in decreasing the compressive strength and these
strength values falls below 20 MPa after 30% partial replacement of cement by flyash. Further, the flyash is partial replaced by
GGBS and then experimental tests were conducted. The cement concrete having binder proportions (50% cement, 30% flyash
and 20% GGBS) provides better mechanical performance and optimum results in economical considerations. Hence the use of
major industrial wastes such as fly ash and GGBS is found to be feasible in the production of new sustainable construction
material.

In this Paper an experimental investigation on the effect of Isfahan Ground Granulate Blast Furnace Slag (GGBS) on the compressive strength development of self-consolidating concrete (SCC) and normal concrete (NC) was performed. For this purpose, Portland cement type I was replaced with GGBS in various Portions. For NC and SCC Mixes 10*10*10 cubic cm specimens was tested in 7, 28 and 91 days. It must stated that in this research water to cement ratio was 0.44,cement used in cubic meter was 418 Kg/m³ and Superplasticizer (SP) Type III used in SCC based on Poly Carboxylic acid. The results of experiments have shown that increasing GGBS Percentages in both types of concrete reduce Compressive strength in early ages.

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— One such type of by-product from the iron smelting industry is iron slag, which is formed from the blast-furnaces of iron industry. This blast furnace slag is used to make a cementitious material by grinding it into a fine powder, which is called Ground Granulated Blast Furnace Slag or GGBS. The same blast furnace slag is used to make a glassy granular product (GBFS) which can be used as fine aggregate. GGBS has cementitious properties and can be very useful in the design and development of high quality cement paste/mortar and concrete. GGBS cement is accessorial to concrete, within the concrete manufacturer's batching plant in conjunction with Portland cement, aggregates and water. Growing ecological limitations to the use of sand from river beds leads to search for alternatives mainly near the larger urban areas. This has brought in brutal strains on the accessibility of sand forcing the construction business to look for substitute building materials without compromising the strength criteria of concrete. Granulated blast furnace slag is one of the promising sustainable solutions as they are obtained as solid wastes generated while production of iron. Hence it eliminates the solid waste disposal problem and other ecological issues. Present experimental work explores the opportunity of using GBFS as replacement of natural sand in concrete and GGBS as replacement of cement in concrete. In our experiments it was found that both GGBS can be used successfully to partially replace cement in concrete by 55%.