Effect of recycled fine aggregates on performance of Reactive Powder Concrete

Abstract

Reactive Powder Concrete (RPC) is a special type of concrete in which traditional coarse aggregates are replaced by fine sand. Its main ingredients include a high percentage of Portland cement, a very low water-to-binder ratio, and the presence of super plasticizer, grey sand and silica fume. The main purpose of this research was to evaluate the performance of RPC produced by replacing the natural fine aggregates (grey sand) with recycled fine aggregates under varying curing conditions. Various properties including compressive strength, flexural strength, tensile strength, sorptivity, water absorption, electrical resistivity, sulphate resistance and resistance against marine environment were studied. Two types of recycled fine aggregates were used; one was obtained from demolished normal strength concrete and second was obtained from demolished RPC. It was found that the compressive strength of all tested samples increased when cured at 90 °C for 48 h, as compared to the samples kept under normal curing conditions. Mechanical properties of RPC prepared with recycled aggregates increased up to 50% replacement, while durability performance gradually reduced with an increase in the recycled aggregate content, but within reasonable limits.