Residual Performance and Damage Restorability of Reinforced Concrete Flexural Column after Earthquake

研究了钢筋混凝土柱弯曲屈服后受剪破坏阶段的轴压承载力。研究了劣化后轴向承载力的可恢复性。对5个尺寸、配筋和材料相同的柱试件进行了试验。它们被设计成抗剪承载力与抗弯承载力相当。在压应力水平为0.2σ_B（σ_B：混凝土抗压强度）的恒定轴向荷载作用下，它们以循环方式承受侧向力，产生反对称弯矩分布。通过横向加载校正残余变形后，对每个试件进行轴向加载，得到以下结论。(1)据观察，轴向强度的恶化是由占主导地位的斜向剪切裂缝在跨中的列，和恶化后立即剪切裂缝发生显着大。(2)基于桁架和拱结构的分析较好地预测了轴向强度的恶化，这与桁架结构中撑杆混凝土压应力的恶化密切相关。（3）在斜向剪切裂缝中注入环氧树脂可以很好地恢复梁的横向和轴向强度。

The axial capacity of reinforced concrete columns during shear deterioration after flexural yielding was investigated. The restorability of the axial capacity after the deterioration was also studied. Five column specimens with the same dimensions, reinforcement and materials were tested. They were designed that the shear capacity was equivalent to the flexural capacity. They were subjected to lateral forces in a cyclic manner producing anti-symmetric bending moment distribution under a constant axial load equivalent to 0.2σ_B in the compressive stress level (σ_B : compressive strength of concrete). Each specimen was loaded in the axial direction after corrected the residual deformation by the lateral loading.The following conclusions were obtained.(1) It was observed that the deterioration of the axial strength was caused by dominant diagonal shear cracks in the mid-span of columns, and the deterioration was significantly large immediately after the shear cracks occurred.(2) The analysis based on truss and arch mechanisms well predicted the deterioration of axial strength, which related strongly the deterioration of concrete compressive stress of strut in truss mechanism(3) The injection of epoxy into the diagonal shear cracks was effective to recover the lateral and axial strength perfectly.