Renewing Singapore's urban infrastructure - Recycled aggregates can make the grade

Abstract

Research study at the National University of Singapore is aimed to find a method involving differences between the electromagnetic and thermal properties of the coarse granite aggregate and adhering cementitious mortar to improve the quality of Recycled Concrete Aggregates (RCA). Analytical modeling was used for the proposed microwave beneficiation system that utilized three frequencies 2.45GHz, 10.6GHz and 18GHz representative of the characteristics of typical low, intermediate, and high frequencies. Results show that a high temperature differential may be developed especially at the interface between the granite aggregate and the adhering cementitious mortar. The significant effects of RCA water content and microwave frequency on the beneficiation process are also confirmed. The significant effects of RCA water content and microwave frequency on the beneficiation process are confirmed.