高温后钢骨再生混凝土柱的加固疲劳行为

针对大量建筑物在火灾中损坏急需修复，对高温（500º）后钢骨再生混凝土柱进行了纤维复合材料（CFRP）加固前后的静力轴压试验和加固后的疲劳实验，通过对破坏模式、承载力、荷载-位移曲线和荷载-应变曲线进行分析，结果表明：CFRP能有效提高高温后钢骨再生混凝土柱抗压强度，刚度和延性，承载力提高幅度最高可达141%；当再生混凝土取代率为50%时,CFRP加固短柱取得最大承载力；加固试件破坏形式为CFRP拉断、内部混凝土压碎以及钢骨上部屈曲，未加固试件的破坏形式为钢骨上部屈曲，外部混凝土剥落；加固后的钢骨再生混凝土柱305RF能够在上限为50%承载力的荷载下经过200W次疲劳试验，200W次后试件最大竖向位移接近相同试件静力破坏时对应位移。

Fatigue Behavior of Steel Reinforced Recycled Concrete Columns after High Temperature Reinforced By CFRP

In order to repair many structures damaged after fire, the static axial compression test of steel reinforced recycled concrete columns (SRRCC) after high temperature was taken in two states: reinforced by CFRP or not. And the fatigue test was performed on the SRRCC after high temperature reinforced by CFRP. According to analysis on the failure mode, bearing capacity, load-displacement curve and load- strain curve, the results showed that: The CFRP could improve efficiently the compressive strength, ductility and stiffness; the increase rate could reach to 141%. The specimens whose replacement rate was 50% reinforced by CFRP get the maximum bearing capacity; the failure of reinforced specimens was caused mainly by CFRP pulled out, internal concrete crushed and upside of steel ribs buckled, while the non-reinforced specimens was failure induced only by upside of steel ribs buckled; the fatigue life of specimen 305RF under the maximum load equaled to 50% its bearing capacity exceed 200W cycled. The max vertical displacement at 200W cycles approached to that of static compression test.