Strengthening of Recycled Coarse Aggregate using Different Surface Treatment Techniques

Abstract

Numerous studies performed on recycled aggregate indicated that recycled aggregate has the undesirable characteristics of porosity, high water absorption, and low crush resistance due to the presence of porous mortar as well as the tiny seams derived from the crushing process. This study involves strengthening of RA using various surface treatment techniques like treatment with pozzolan slurry (fly ash, alccofine and cement slurry), HCl, polyvinyl alcohol and an optimized triple mixing method. The physical and mechanical properties of RA were comprehensively assessed before and after the surface treatment. The optimum percentage of replacement of natural coarse aggregate with treated recycled coarse aggregate is also found out based on compressive strength. It suggests that treatment using fly ash and cement pozzolan slurry is an efficient and feasible method for improving the mechanical properties of recycled coarse aggregate. This treatment of recycled coarse aggregate is not only an efficient way for enhancing the properties of recycled aggregate, but also an environmental friendly approach. Also the optimum percentage replacement of treated recycled aggregate was obtained as 60%.