Evaluation of self-compacting concretes produced with ternary and quaternary blends of different SCM and hydrated-lime

Abstract

Self-compacting concrete (SCC) is a high-performance concrete that has gained prominence in recent years due to its high fluidity and cohesion characteristics. In this material, the use of supplementary cementitious materials (SCM) is necessary for the consolidation properties and durability requirements to be achieved. SCM obtained from waste or industrial by-products can improve SCC properties and reduce the environmental impact associated to Portland Cement (PC) production. In light of these facts, the present paper addressed the effects of high levels of mineral additions (metakaolin, rice husk ash and limestone filler) and hydrated-lime on the physical (ultrasonic pulse and capillary absorption), mechanical (compressive strength) and durability (carbonation resistance, chloride ion diffusion and electrical resistivity) properties of SCC. The results showed that metakaolin and rice husk ash increase the viscosity of SCC due to their larger specific surface area. The simultaneous incorporation of high content of mineral additions reduced the compressive strength of SCC. However, it was possible to obtain concretes with compressive strength between 22 and 46 MPa at 28 days and with adequate physical performance and durability. The addition of hydrated-lime to SCC proved efficient, mainly due to reduced carbonation depth associated to alkaline reserve replacement.