Influence of limestone size and content on transport properties of self-consolidating concrete

This study assessed influences of limestone powder' size and content on compressive strength and transport properties of self-consolidating concrete (SCC). Several SCC mixtures were prepared with uniform water-to-cementitious materials ratio and powder content (cement + fly ash + limestone) of 0.45 and 475 kg/m3, respectively. Class F fly ash substituted 20% by weight of cement and 10, 15 and 20% of total cementitious materials was replaced with limestone powder having average particle size of 3 or 8 μm. Slump flow of 635 ± 25 mm, visual stability index of 0 or 1, and maximum passing ability (difference of slump and J-Ring flow) of 37.5 mm were used for all studied mixtures. The devised experimental program included compressive strength, absorption, rapid chloride penetration (RCPT), rapid chloride migration (RCMT), and water penetration depth. The results of this study revealed that inclusion of limestone powder and reduction in its size were both effective in improving compressive strength and transport properties of SCC. While absorption, volume of permeable voids, water penetration depth, and RCPT improved significantly through use of limestone powder, the improvements were marginal for compressive strength and RCMT. Reduction of limestone powder size had more effect in improving performance of 28-day cured concrete as compared to that of 90 days mixtures.