Study of the seismic response of a recycled aggregate concrete frame structure

Based on six-degree-of-freedom three-dimensional shaking table tests,the seismic response of a recycled aggregate concrete(RAC)frame was obtained.The analysis results indicate that the maximum story shear force and overturning moment reduce proportionally along the height of the model under the same earthquake wave.The story shear force,base shear coefficient and overturning moment of the structure increase progressively as the acceleration amplitude increases.The base shear coefficient is primarily controlled by the peak ground acceleration(PGA).The relationships between the PGA and the shear coefficient as well as between the PGA and the dynamic amplification factor are obtained by mathematical fitting.The dynamic amplification factor decreases rapidly at the elastic-plastic stage,but decreases slowly with the development of the elastic-plasticity stage.The results show that the RAC frame structure has reasonable deformability when compared with natural aggregate concrete frame structures.The maximum inter-story drift ratios of the RAC frame model under frequent and rare intensity 8 test phases are 1/266 and 1/29,respectively,which are larger than the allowable value of 1/500 and 1/50 according to Chinese seismic design requirements.Nevertheless,the RAC frame structure does not collapse under base excitations with PGAs from 0.066 g up to 1.170 g.