PROPERTIES OF FULL SCALE SPECIMENS WITH RECYCLED COARSE AGGREGATE CONCRETE PROCESSED BY A DECOMPRESSION AND RAPID RELEASE PROCEDURE (DC-RR)

Abstract

This study proposes an unique technique for improving qualities of concrete with recycled concrete coarse aggregate; a decompression and rapid release (DC-RR). The DC-RR procedure is applied after normal mixing of concrete with recycled aggregate. Through the DC-RR procedure, the micro structure of interfacial transition zones between recycled aggregate and new matrix mortar are estimated to be dramatically improved. In this paper, experimental studies with full scale specimens are described on the effectiveness of the DC-RR procedure on the performances of concrete structures with recycled concrete coarse aggregate, such as core strengths of columns, defections of slabs and crack widths of walls. It was found that, by applying the DC-RR procedure, the performances of full scale concrete specimens with recycled coarse aggregate were much improved and evaluated as almost equal to those with natural coarse aggregate.