Mechanical characteristics and recoverability of low-quality crushed coarse aggregate by surface modification and microwave heating

Abstract

This paper presents a quantitative review of the mechanical performance, as well as the separation from the matrix and the recovery performance of surface-modified coarse aggregate manufactured from lowquality crushed coarse aggregate (LCCA) coated in an inorganic powder. The results of the experiments showed that reinforcing the interfacial transition zone, a vulnerable area in concrete, by coating the surface of the LCCA with a surface modification material, can help reduce micro-cracking and improve the structural integrity of the aggregate. Therefore, the use of coated LCCAs resulted in concrete of improved strength and durability. Further, it was demonstrated that the dielectric material (Fe2O3) present in the inorganic coating layer (surface modification coarse paste) could be heated effectively by microwaves. The results can be explained by an increase in void volume, along with a weakening of the hydrated cement paste, promoting the efficient recovery rate of surface-modified LCCAs.