Experimental study on frame structures with recycled aggregate concrete under lateral cyclic loads

This paper presents an experimental study on the seismic behavior of frame structures made with recycled aggregate concrete (RAC). Three 1:2 scaled frame specimens were tested under lateral cyclic loads and constant vertical load. One of these frames was conventional concrete frame, while the remaining two frames were RAC frames with a recycled coarse aggregate (RCA) replacement percentage of 25 and 50%, respectively. The structural performances, in terms of the failure pattern and mechanism, ultimate lateral load capacity, hysteretic response, backbone curve, ductility capacity, energy dissipation capacity and stiffness degradation were analyzed in detail. The effect of RCA replacement percentage on the seismic performance of RAC frames was investigated carefully. The experimental results indicate that the seismic performance of RAC frame is similar to that of conventional concrete frame and not significantly affected by the incorporation of RCA. All of the tested frames behaved with the same failure pattern, which is a ductile failure mechanism. The average value of the ductility coefficient and the equivalent viscous damping ratio of the RAC frame are 3.55 and 0.089, respectively. The RAC frame structure with an RCA replacement percentage of 50% still has adequate capabilities of ultimate strength, deformation and energy dissipation and is able to withstand an earthquake attack.