配置高强钢筋与普通钢筋的预制桥墩滞回性能试验

预制拼装桥墩的抗震性能是桥梁工业化技术的研究热点之一。在预制拼装桥墩的设计中，采用高强钢筋替代普通强度的钢筋，可以减少钢筋用量，加快接缝面的钢筋连接速度，然而，其抗震性能需要进一步研究。为对比钢筋强度对预制拼装墩柱的抗震性能影响，制作了2个具有相同尺度的混凝土试件，分别配置高强钢筋（HRB600E）和普通强度钢筋（HRB400），开展滞回加载试验研究。结果表明：采用高强钢筋的预制拼装桥墩，具有较大的等效屈服强度和极限强度，且在塑性阶段，其极限位移和屈服后位移角增量也显著增加，同时，其较小的滞回耗能和残余位移，表明这种桥墩具有较小的塑性损伤和较好的自恢复性能；采用高强钢筋的预制拼装桥墩的刚度退化速度较为缓慢，残余刚度大，有利于震后应急通行和修复。最后，本文还对高强钢筋与普通强度混凝土在预制拼装桥墩中的联合使用进行了合理性论证。研究成果可为预制拼装桥墩抗震设计提供参考。

Experiment on Hysteretic Behaviors of Precast Piers with High-strength and Conventional Steel Rebar

Seismic performance of precast bridge piers is one of the most researched topics in the field of industrialized construction. In the design of precast bridge piers, implementing high-strength rebar to replace conventional steel rebar can reduce reinforcement quantity and accelerate the operation of connecting the steel rebar through the joint surface. However, its seismic performance needs to be further studied. To compare the impact of rebar strength on seismic performance of precast piers, two pier specimens were fabricated with the same geometry and concrete grade and reinforced with high-strength rebar (HRB600E) and conventional strength rebar (HRB400), respectively. Then, hysteretic loading tests of the two piers were conducted and their results were compared. The research results demonstrate that the precast pier reinforced with high-strength rebar has a larger equivalent yield strength and ultimate strength. While in the plastic stage, ultimate displacement and post-yielding drift increment extends significantly. Simultaneously, the lower energy dissipation and residual displacement indicate that these types of bridge piers have less plastic damage and better resilience performance. Compared to the precast pier with conventional rebar, the stiffness degradation rate of precast bridge piers with high-strength rebar is lower and the residual stiffness increases, which facilitate emergency traffic operation and rehabilitation. Finally, a discussion is also made on the practicality of the combined use of high-strength rebar and medium-strength concrete in precast piers. The findings in this paper help in the design of seismically resilient precast piers with different rebar strengths.