Performance of Recycled Coarse Aggregate Concrete Incorporating Metakaolin

Abstract

The civil engineering industry is currently facing significant challenges of how to be an eco-friendly industry. The thoughtful utilization of natural resources in construction practices and the usage of recycled materials in the production of concrete can be a solution. In this experimental study, the behavior of recycled aggregate concrete (RAC) incorporating 100% recycled coarse (RC) aggregate is examined. It investigates the workability and mechanical properties of concrete after total replacement of natural coarse (NC) aggregate with RC aggregate. The influence of using Metakaolin (MK) at contents of 4, 8, 12, 16, and 20% on RA concrete performance is assessed. In total six mixes (one without MK and five included MK). A reference mix made with NCA was also prepared for comparison reasons. Workability, mechanical properties, water absorption (WA), and dynamic modulus of elasticity (Ed) were determined. The obtained results reveal that MK reduces the workability of the RAC. However, MK results in compressive strength enhancement and dynamic modulus of elasticity improvement, and lower water absorption of recycled aggregate concrete.