Analysis of the Ductility Behaviour and Mechanical Properties of Waste Concrete

Abstract

The increasing generation of construction and demolition waste has prompted the exploration of sustainable alternatives in the construction industry. This study investigates the ductility behaviour and mechanical properties of concrete incorporating recycled concrete aggregate (RCA) derived from waste concrete. Various mix proportions were prepared by partially and fully replacing natural coarse aggregates with RCA at replacement levels of 0%, 25%, 50%, 75%, and 100%. Standard concrete specimens were cast and tested to evaluate compressive strength, split tensile strength, flexural strength, and modulus of elasticity. Ductility was assessed based on load-deflection characteristics under flexural loading to determine energy absorption and ductility index. The experimental results indicate that while mechanical properties tend to decrease with higher RCA content, concrete with up to 50% RCA demonstrates acceptable strength and enhanced ductility due to increased micro-crack propagation and improved energy dissipation. The study concludes that waste concrete can be effectively reused in structural and semi-structural applications, offering both environmental and economic benefits. This work contributes to the broader goal of sustainable construction by promoting resource conservation and reducing landfill pressure.