Seismic performance of steel-reinforced reactive powder concrete columns

Abstract

The seismic performance of the innovative steel-reinforced reactive powder concrete (SRRPC) composite columns was evaluated via the cyclic experiments considering the steel shape ratio, axial compression ratio and the stirrup ratio. The SRRPC columns generally exhibited appreciable seismic behavior, great crack-resistance and excellent anti-spalling property. It was found that increasing the steel shape ratio from 4.20% to 5.35% can significantly enhance the ductility and the energy dissipation capacity. As the axial compression ratio increased from 0.1 to 0.3, the peak lateral load increased but the ductility significantly decreased. Increasing the stirrup ratio from 1.57% to 2.52% was not helpful for seismic performance in the pre-peak zone but was beneficial to the strength and ductility in the post-peak zone. Moreover, the average strength loss of the SRRPC columns with low axial compression ratio at the 4.5% drift ratio was less than 12.5%, satisfying the modern seismic drift criteria. Two coefficients, βtu and k, for predicting the equivalent tensile strength were identified and compared to the suggested values from the specifications JGJ/T 465-2019 and T/CCPA 35-2022, respectively. An analytical model was successfully developed to predict the lateral load-bearing capacity. Good agreements were found between the experimental and analytical results.