Microwave-assisted beneficiation of recycled concrete aggregates

Abstract

The presence of adhering cementitious mortar has been reported to be one of the main factors lowering the performance of concrete mixtures made with recycled concrete aggregates (RCA) when compared to natural aggregates (NA). A new microwave-assisted technique has been recently developed at the National University of Singapore that may increase the yield and quality of the RCA processed within a much shorter time when compared to other previously proposed methods. In this paper, the results of an experimental study conducted to investigate the effect of the adhering mortar content on the properties of RCA and to compare efficacy of the microwave-assisted beneficiation technique with the acid pre-soaking, and conventional heating beneficiation techniques proposed in available literature are presented.