Seismic Performance of Recycled Aggregate Concrete Block Structures
The experimental study was focused on the seismic performance of recycled aggregate concrete (RAC) hollow block walls confined by ring beam and tie column under low cyclic horizontal loading. Investigations on the damage process, failure mode, load bearing, and deformation capacity show that the hollow block wall with RAC has favorable displacement ductility and energy dissipation capacity. Furthermore, the contribution of ring beam tie column system to the seismic performance of RAC hollow block walls was also examined. The results show that the vertical compression stress of RAC hollow blocks is the main factor influencing the seismic performance, whereas the reinforcement ratio for ring beams and tie columns only has limited effects. Compared with the hollow block wall with NAC, the hollow block wall with RAC has similar seismic performance. Furthermore, a full scale model of a RAC block masonry building with the tie column ring beam cast in situ slab system, was tested on the MTS shake table. The natural frequency, equivalent stiffness, structural damping ratio, acceleration response, seismic force response, displacement response, base shear response, structural fragility, etc. were analyzed and discussed. The test results demonstrate that RAC block masonry structure confined by the "tie column ring beam" system is a good solution to withstanding earthquakes. The storey drift ratio and the overall behavior satisfy requirements of the Chinese design code. Generally, RAC block masonry structure bounded by the tie column ring beam system with proper design exhibits good seismic behavior and can resist earthquake attacks under different seismic levels.