Durability behaviour of self-compacting concrete containing high-volume fly ash and alternative aggregates

This study presents utilisation of High-Volume Fly Ash (HVFA) in design of Self-Compacting Concrete (SCC) containing alternative aggregate particles. The class-F Fly Ash was used in a binary blend of Portland Cement at a fixed dosage of 50% by weight of powder and natural coarse and fine aggregates were replaced with coarse and fine Recycled Concrete Aggregates (RCAs), respectively, at replacement levels of 0%, 50% and 100% by volume. Durability properties of the SCC mixes were studied using rapid chloride penetration test, initial surface absorption test and capillary suction test. Results of the study showed that concrete mix made with replacement of natural coarse aggregates with 50% coarse RCAs, concrete mix made replacement of natural fine aggregates with 50% fine RCAs and concrete mix made with replacement of both natural coarse and fine aggregates with the respective RCAs at 50% replacement level exhibits satisfactory performance without compromising their fresh and hardened state properties. Furthermore, the incorporation of HVFA in SCCs improved the hardened state properties at later ages of curing due to the secondary pozzolanic reaction.