Experimental Assessment of Various Treatment Techniques for Enhancing the Properties of Different Types of Coarse Recycled Concrete Aggregate

The utilization of Recycled Concrete Aggregate (RCA) is becoming an exciting issue in Canada and globally, due to many reasons, including lowering consumption of natural materials, decreasing waste materials in landfills and reducing environmental problems. This research’s main objective is to investigate the effect of various treatment techniques on enhancing the physical and mechanical properties of two different Coarse Recycled Concrete Aggregate (CRCA) types. Heat treatment was performed at temperatures ranging between 250 and 750 °C. The presoaking method included the application of strong and weak acids represented by HCl and C₂H₄O₂, respectively. The obtained results indicated that compared to untreated CRCA, a critical improvement is registered in the physical and mechanical properties of both types of treated CRCA due to the utilization of various treatment techniques. A significant difference is highly noticeable between CRCA#1 and CRCA#2 regarding physical and mechanical properties. The utilization of weak acid is more effective and suitable for all aggregate types. Of different treatments, the heat treatment at 350 °C had a maximum influence concerning enhancing various CRCA properties. The abrasion test results suggest that CRCA#2 has a lower amount of attached adhered mortar to the aggregate surface. Physical properties of CRCA, including water absorption and porosity, are strongly correlated with durability characteristics in terms of resistance to abrasion under the influence of heat treatment.