Study on the Axial Compression Performance of UHPC-SRC Short Columns

This study proposes a novel UHPC-SRC short column structure that adopts ultra-high performance concrete (UHPC) as a permanent formwork, combined with longitudinal reinforcement, stirrups, and H-shaped steel. The design aims to enhance construction efficiency and sustainability while maintaining excellent mechanical performance. A finite element model was established in ABAQUS to simulate the compressive behavior of the structure, incorporating key parameters such as reinforcement diameter, formwork thickness, and steel section strength. The results indicate that increasing the formwork thickness and strength can significantly improve the ultimate load-bearing capacity, with a thickness increase leading to an enhancement of up to 23% in ultimate load. In contrast, the reinforcement ratio and steel strength exert relatively minor effects on the overall performance. Validation against experimental data shows an average ratio of 0.963 between experimental and simulated values, indicating high model accuracy. The observed failure mode is characterized by concrete cracking and fragmentation, with longitudinal reinforcement yielding being the dominant failure mechanism. The proposed formula for calculating axial compressive bearing capacity has been verified as highly reliable, with calculation results in close agreement with finite element simulations, thereby providing strong support for engineering design and practical applications.