Mechanical Properties of Concrete with Recycled Concrete Aggregate for Sustainable Construction

The application of recycled concrete aggregate (RCA) in concrete construction offers a sustainable replacement for conventional natural aggregates, endorsing resource preservation and minimizing waste in construction. The mechanical properties of concrete including RCA and the influence of stainless-steel fibers (SSFs) were investigated in this study. Concrete samples with varying RCA replacement ratios and SSF dosages were tested to evaluate the workability, density, compressive strength, and tensile strength. The RCA’s higher absorption, angularity, and residual mortar negatively affected the workability of the concrete mix. The addition of RCA can slightly decrease strength due to increased porosity and weaker interfacial bonding, the addition of SSF improved the mechanical properties by improving crack resistance. With appropriate mix adjustments, SSFs can overcome the RCA drawbacks and make the RCA concrete as a promising eco-friendly material for sustainable construction. The addition of 0.5% SSFs significantly improved tensile strength, raising the value to about 4.5 MPa at 0% RCA, an increase of nearly 35%.