Experimental Investigations to Determine the Chloride attack on Medium and High Strength Concrete under the Influence of GGBS

Concrete is a widely-used material in construction industry, because it has naturally and easily available ingredients like cement aggregate and water. Production of cement creates environmental problem like emission of CO2 in the production process of cement. So, there is serious need to find ways and means to reduce CO2 emission. To overcome this problem Ground Granulated Blast Furnace Slag, which is a pozzolanic material can be used as a partial replacement to cement. The main components of GGBS are CaO (30-50%), SiO2 (28-38%), Al2O3 (8-24%), and MgO (118%). In general, increase in CaO content of the slag increases slag basicity and therefore improves the compressive strength. As it is available from the literature, strength and durability are the two important mechanical properties to make reliable concrete. Many investigations are available on the strength properties of GGBS concrete with different replacement levels of GGBS. However, durability studies on medium and high strength concrete over different replacement levels of GGBS. In the present study, GGBS was replaced with cement to obtain the influence of GGBS in normal and high strength concrete on durability properties. Comparisons were made with different percentage of replacements of GGBS for cement, which helped to arrive at the optimum percentage of replacement. Cement was replaced by GGBS at 0, 20, 30, 40 and 50% by weight of cement in conventional concrete and high strength concrete. Over 200 cubes and cylinders were casted, cured and tested for 28 and 56 days. Various durability tests were conducted on specimens such as, sulphate resistance, acid attack, and compression strength and water absorption test. Keywords— Chloride attack, GGBS replacement, Residual strength.