Performance of steel tube reinforced concrete-filled weathering steel tubular members under lateral impact loading

Abstract

Weathering steel tube is superior to mild steel tube in corrosion resistance, but it is less used in engineering projects due to its high price. To balance the performance and cost, mild inner steel tube reinforced concrete-filled weathering steel tube (STRCFWST) members are proposed in this study, and the lateral impact loading test is carried out. The impact responses of concrete-filled weathering steel tube (CFWST) members and STRCFWST members are studied and compared experimentally. It is indicated that the presence of the inner steel tube can remarkably enhance the impact resistance of STRCFWST members. The outer steel tube has a stronger influence over the impact resistance as compared to the inner steel tube. A constitutive model for the weathering steel is developed based on the material test results. The impact performances of STRCFWST, CFWST and conventional CFST members are compared and discussed using numerical simulation. Finally, parameter analysis of the impact performance of STRCFWST members is carried out by taking into account the actual stress state of bridge bents. The results show the proposed model can predict the mechanical behaviors of weathering steel, making it suitable for numerical modeling. The CFWST member suffers fracture failure a little earlier than the CFST member. A large diameter-thickness ratio is recommended for inner steel tubes on the premise of guaranteeing construction conditions. The optical area ratio of internal and external steel depends on the prices of weathering steel and mild steel, and the diameter ratio of inner and outer steel tube.