Properties of the foam concrete containing waste brick powder derived from construction and demolition waste

Abstract

Foam concrete has a low density and excellent functionality, which has been widely used in construction applications. Considering the recycling and reusing of waste clay brick from construction and demolition waste (CDW), the clay brick powder (CBP) derived from waste clay brick was used as the supplementary cementitious material (SCM) to prepare foam concrete in this paper. The foam concrete with various densities and CBP replacements were first prepared, and then the drying shrinkage, mechanical properties, water absorption and pore distribution were determined. The results show that the CBP possesses the fundamental characteristics of SCM, and the pozzolanic index of high fineness CBP is approximately 89.6%. The added CBP has no obvious impact on the dry apparent density and pore distribution of foam concrete. Incorporating CBP reduces the drying shrinkage of foam concrete, and the maximum shrinkage ratio and CBP replacement follows a good relationship. The compressive strength of foam concrete with CBP up to 15% is similar to and even higher than that of the foam concrete without CBP; however, the compressive strength decreases with the further increase of CBP replacements. The effects of CBP content on the properties of low-density foam concrete are more obvious than those of the high-density foam concrete. In particular, the utilization of CBP in foam concrete preparation has excellent recycling efficiency, economic and environmental benefit.