Investigation of carbonation resistance of recycled aggregate concrete

Abstract

This paper studied the carbonation resistance of recycled aggregate concrete (RAC) designed by two mix proportion design methods through accelerated carbonation test. The investigated variables include water-cement ratio, replacement ratio of recycled coarse aggregate (RCA), and carbonation time. Based on the test results, the effects of water-cement ratio, replacement ratio of RCA, mix proportion design method, and carbonation time on the carbonation resistance of RAC were analyzed and discussed. The results showed that the mix proportion design method has a significant effect on the carbonation resistance of RAC. The replacement ratio of RCA and the water-cement ratio alternately affected the carbonation resistance of RAC. The replacement ratio of RCA is the major factor affecting the carbonation resistance of RAC. In addition, a carbonation model for RAC considering the effect of the mix proportion design method was proposed. The comparison of the test values and calculated values indicates that the proposed model can properly predict the carbonation depth of RAC.