Experimental studies on behaviors of reinforced concrete column structures made of recycled aggregates under concentric loads

Abstract

The paper presents experimental results and structural analysis of reinforced concrete (RC) columns made of recycled aggregate concrete (RAC) and natural aggregate concrete (NAC) under concentric compressive load. The ratio of recycled aggregates in mixture (i.e, replacement ratio, r in %) was 0, 50, and 100% by mass, where r = 0% corresponding to NAC. The load and deformation curves including cracking load, ultimate load, crack width, and compressive strain of the tested columns, were analyzed to determine the effects of replacement ratio of recycled aggregate on the behaviors of square column structures. The results show that the increase of r reduced the load-carrying capacity of RC columns under the concentric compressive load. Horizontal and vertical cracks also were observed immediately for tested columns with high r. The effect of r of RAC on the mechanical behaviros, however, became relatively small and did not affect the behaviors of RAC columns, indicating that the RAC tested in this study was feasible for use in recycled concrete structures.