Effect of up to 12% substitution of clinker with limestone on commercial grade concrete containing supplementary cementitious materials

This paper presents the results of a test program conducted to determine the effect of up to 12% limestone addition in cement on properties of concrete for durable applications. Cement samples with 5%, 7.5%, 10% and 12% limestone content were used and concretes were made with different binder combinations incorporating one or more of fly ash, slag and amorphous silica, applicable for durable applications. Fresh concrete properties including slump, air content, bleed and setting time were investigated and no adverse effects were found. Hardened properties examined included compressive strength, drying shrinkage, chloride resistance and volume of permeable voids. The results revealed a minor effect on concrete strength, though performance depended on the binder composition. Drying shrinkage of concrete was found to be similar for all concretes investigated. For mixes containing slag, chloride resistance was improved with increasing limestone content.