Study on Eccentrically-compressed Performance and Influencing Factors of Prestressed Steel Reinforced Members.

Reinforcement treatment for the damaged structure can guarantee the continued safe use of the building. This paper proposes a new prestressed column reinforcement technology for traditional steel structure reinforcement technology by using space profile steel structure instead of angle steel and combining prestressing technology and bolt connection. According to different constraint forms, 4 types of members were designed, and the eccentric compression test and finite element parameter analysis were carried out. The experimental study found that, after being reinforced by prestressed lattice steel, the ultimate load-carrying capacity of the specimen was increased by 49.2%, stiffness by 28%, and deformation capacity by 15%. Compared with the traditional angle steel reinforcement, the reinforcement effect is improved by more than 20% under the same cross-section steel consumption condition. Prestressing can significantly improve the utilization of steel, and steel strain increases by about 30%. At the same time, applying prestressing can improve the stress state of the concrete and steel rebar of the core column. The various parts of the reinforced specimen work together better, and the integrity is enhanced. Based on the test, a parametric analysis was carried out, mainly considering the effects of material strength, eccentricity and steel plate thickness. It was found that increasing the thickness of lattice steel can effectively improve the specimen bearing capacity and ductility, and the strength ratio of reinforcement to lattice steel is about 0.16. However, increasing the strength of steel does not have a significant effect on the bearing capacity. The deformation capacity occurs to be reduced, and using high-strength steel is not recommended. By applying prestressing, stronger restraint can be provided to the reinforced columns, and the reinforcement effect is significantly better than that of angles, which has better engineering application value. [ABSTRACT FROM AUTHOR]