Performance enhancement of the recycled aggregate concrete properties using blended sand

Abstract

Massive consumption of River sand in construction activities around the world led to the depletion of natural resources. Demolition waste was gaining popularity as a substitute for sand, but recycled fine aggregate(RFA) exhibits poor performance in concrete in terms of strength and workability. Therefore, the current study is a small attempt to improve the properties of RAC (Recycled aggregate concrete) by applying blending of RFA with copper slag (CS) to form blended sand. The study investigates the use of recycled fine aggregate (RFA) and blended sand (RFA + CS) separately in M−40 grade of concrete at 20%, 40%, 60%, 80% and 100% replacement levels of natural sand. Then concrete mixes are checked for workability (slump value) and compressive strength at 7, 14 and 28 days of curing. Results show that RFA concrete presents poor properties. In contrast, improved results were obtained in the case of blended sand concrete, which performed even better than reference samples prepared with river sand at 20% replacement of natural sand. Therefore, the study concluded that the enhancement in properties of recycled aggregate concrete(RAC) was achieved by using proper blending material in the required proportion with RFA. Further, the finding reveals that blended sand can use to enhance the strength and workability of concrete and have the potential as a sustainable alternative to river sand that brings sustainability to the construction sector.