Effect of Addition of Combination of Admixtures on the Properties of Self Compacting Concrete Subjected to Sulphate Attack

Abstract

This paper presents an experimental investigation on the effect of acid attack on the properties of SCC produced by the combination of admixtures such as (Superplasticizer + Viscosity modifying admixture +Air entraining agent + Accelerator), (Superplasticizer + Viscosity modifying admixture +Air entraining agent +Retarder), (Superplasticizer + Viscosity modifying admixture +Air entraining agent + Water proofing compound) and (Superlasticizer + Viscosity modifying admixture +Air entraining agent + Shrinkage reducing admixture). The concrete testing specimens was prepared by a mix proportion 1: 2.7: 6.1: 5.1 with cement: fly ash: sand: coarse aggregate with a water/binder ratio of 0.38. Specimens after 28 days of curing were immersed in magnesium chloride solution of 5% and 10% concentrations for 90 days. Before immersion, they were weighed accurately. After 90 days of immersion, the specimens were removed from chloride media, washed in running water, weighed accurately and tested for their respective strengths. Before testing, the specimens were drilled to a depth of 30mm. The powder collected in this manner was titrated against AgNO3 solution to find chloride content in the concrete. SCC produced with above combination of admixtures show better resistance to chloride attack as compared to SCC produced with combination of admixtures (SP+VMA) only.