FRP约束配筋HPFRCC圆柱抗震性能研究

In order to improve the tensile strain-hardening behavior of high-performance fiber-reinforced cement composites (HPFRCC) subjected to axial compression and keep the compatibility of deformation between HPFRCC and steel reinforcements in the plastic hinge regions of members, the constraints of fiber-reinforced polymer (FRP) to enhance the fiber-bridging effect of HPFRCC are employed. A novel FRP-confined steel-reinforced HPFRCC circular column is presented. The effects of the axial load ratios and FRP restraint forces on the seismic behaviors of steel-reinforced HPFRCC circular columns will be investigated by the quasi-static cyclic loading tests. The cracking distribution, damage tolerance and failure mechanism in plastic hinge regions of columns will be determined. The cyclic behavior, displacement ductility and energy dissipation capacity of the column specimens will be analyzed. The load-deformation analyzing model of the column specimens is proposed. On the basis, the finite element method will be used to analyze the elastic-plasticity behaviors of the specimens, simulate the whole process of failure and predict the ultimate state and seismic behavior of the columns. The research results will be of great theoretical significance and practical value to improve the seismic performance of HPFRCC structures.

为改善轴压作用下高性能纤维增强水泥基复合材料（HPFRCC）的受拉应变硬化性能，保持构件塑性铰区HPFRCC与钢筋的协同工作，利用纤维增强复合材料（FRP）约束对HPFRCC纤维桥联作用的增强机理，提出FRP约束配筋HPFRCC圆柱新型抗震构件。通过开展低周循环往复试验，深入研究轴压比、FRP约束等因素对配筋HPFRCC圆柱抗震性能的影响；确定试件塑性铰区的裂缝分布特征、损伤容限以及破坏机理；分析柱的滞回行为、位移延性和耗能能力，提出柱试件的荷载-变形计算模型。在此基础上，利用有限元方法进行构件弹塑性分析，模拟柱的整个破坏过程，预测构件的极限状态和抗震性能。该成果对于提高HPFRCC结构的抗震性能具有重要的理论意义和实用价值。

为了能延缓轴压作用下高性能纤维增强水泥基复合材料（HPFRCC）的损伤扩展，确保材料受拉应变硬化性能的持久发挥，利用复材（FRP）约束水泥基材料呈现出的轴压强化特性，提出将复材约束配筋HPFRCC组合构件应用于结构抗震领域。通过轴压性能试验表明，复材约束HPFRCC的轴压性能不同于普通混凝土，故提出更适用的轴压应力-应变本构模型。根据构件拟静力试验的研究结果可知，复材约束配筋HPFRCC圆柱能提高构件的耗能性能和耐损伤性能。基于现象观察和理论分析，揭示了模拟地震作用下构件的损伤机理及破坏模式。通过改进和设计变形量测装置和摩擦力测试装置，定量给出了构件在不同机制作用下的变形比例；并且，消除了摩擦力对试件恢复力的干扰影响。在此基础上，建立了考虑复材约束作用和HPFRCC受拉应变硬化特性的圆形正截面柱压弯承载力计算公式和数值分析方法。该研究成果有助于提高我国建筑、桥梁工程的抗震性能，对国民经济和人身安全起到重要的保障性作用。