Hysteric model and pushover analysis of steel-reinforced reactive powder concrete columns

The use of high-strength concrete (HSC) for the steel-reinforced concrete (SRC) columns received wide attentions due to the inherent brittleness of HSC. To simultaneously enhance the strength and the ductility, a new type of steel-reinforced reactive powder concrete (SRRPC) column was developed. However, the seismic performance of the SRRPC column has not been well understood. Based on the previous cyclic experimental results, a theoretical hysteretic model was developed to simulate the hysteretic loops. Moreover, the Finite element model was successfully developed and validated by comparing the experimental failure modes, backbone curves and strain responses. Furthermore, the comprehensive parametric analysis was conducted based on the numerical model, showing that the lateral load-bearing capacity can be effectively improved by increasing the compressive strength of RPC, steel shape yield strength, steel shape ratio and longitudinal reinforcement ratio. However, high transverse stirrup ratio cannot improve the lateral load-bearing capacity, but it can significantly enhance the post-peak strength. As the axial compression ratio increased from 0.1 to 0.9, the lateral load-bearing capacity increased by 51.4 % while the ultimate displacement dramatically reduced by 45.6 %. Furthermore, as the shear-span ratio increased, the lateral load-bearing capacity obviously decreased although the ductility increased. Therefore, it is recommended that the axial ratio and the shear-span ratio should be reasonably controlled in the design of the SRRPC column.