Flexural performance of recycled aggregate concrete beams containing waste concrete and bricks

The recycled aggregate made from the demolition of old houses in the last century contains a lot of red bricks. There are obvious differences between red bricks and waste concrete in properties. However, the current treatment process of construction solid waste cannot efficiently separate brick aggregates. To provide a reasonable solution for the efficient and rational use of recycled aggregate concrete containing waste concrete and red bricks, three beams made with natural aggregate concrete (NAC) and three beams made with recycled aggregate concrete (RAC) containing waste concrete and bricks with strengths of C25, C30 and C35 were designed. Bending tests were carried out on six beams to analyze the differences in the process of stress, failure characteristics, deformation capacity, ductility and bearing capacity between RAC beams and NAC beams of the same strength. The results show that in the process of loading to failure, the RAC beams show three stress stages similar to the NAC beams, which also accords with the plane section assumption. However, compared with the NAC beams of the same strength, the ultimate bearing capacity of the RAC beams is slightly smaller, the loading cracks on the surface of beams are more likely to generate and develop during the loading process, the stiffness decreases more significantly, the deformation is greater, the deformation developed from yield to failure is smaller, and the ductility is poor. © 2021, Editorial Office of Journal of Building Structures. All right reserved.