Influence of recycled concrete aggregates and Coal Bottom Ash on various properties of high volume fly ash-self compacting concrete

The mechanical and durability behavior of Recycled concrete aggregates (RCA) based High volume fly ash-Self compacting concrete (HVFA-SCC) has been examined through detailed experimental investigation. The article explores the overall behavior of HVFA-SCC made with 0%, 25%, 50%, 75% and 100% of RCA with alteration of Natural coarse aggregates (NCA) and in conjunction with 10% of Coal bottom ash (CBA) as alteration of Natural fine aggregates (NFA) through evaluation of several properties. Various mechanical tests (Compressive and Tensile strength) and durability tests (Accelerated carbonation, Electrical resistivity, Rapid chloride penetration-chloride permeability, Capillary suction, Initial surface absorption, Ultrasonic pulse velocity-UPV) were carried on HVFA-SCC mixes prepared with specific amounts of RCA, Fly ash (FA) and CBA. The findings confirmed the feasibility of HVFA-SCC made with alteration of NFA/NCA with CBA/RCA at specific levels respectively resulting in reasonable performance with respect to aforesaid properties. Projecting three (3) way benefits (i.e. Portland cement (PC) with HVFA; NFA with CBA and NCA with RCA) probably leads to widespread usage and recycling of by-products generated from the coal (FA and CBA) and construction industry (RCA) respectively. Such an effort assures the minimization of concerns like regulation and disposal of coal and construction industry wastes/by-products to a significant extent.