预应力碳纤维条带加固混凝土圆墩抗震性能试验

针对地震灾害中桥墩柱的破坏形态，考虑轴压比变化、预应力大小、纤维布层数和加载顺序等因素的影响，对9根采用与未采用预应力碳纤维条带加固的钢筋混凝土圆形墩柱进行了低周反复荷载试验研究。通过各试件主要破坏形态和滞回曲线的对比，分析了各因素对承载力、延性性能、滞回特性、耗能能力等重要抗震性能指标的影响。结果表明：采用预应力碳纤维条带加固后，柱的承栽力、延性性能、耗能能力均有较大幅度提升；预应力碳纤维条带提供的主动横向约束力能有效抑制斜向剪切裂缝的开展，将圆墩柱的破坏形态由剪切破坏转变为延性较好的弯曲破坏；先施加轴力后进行预应力碳纤维条带加固所得的加固承载力低于后施加轴力的试件。

Test on Seismic Performance of RC Circular Piers Strengthened with Pre-stressed CFRP Belts

Aimed at the failure modes of piers in earthquake, considering the influence of axialcompression ratio, pre-stress of carbon fiber reinforced polymer (CFRP) belts, layers of CFRPbelts and loading sequences, test on nine RC piers strengthened with pre-stressed CFRP beltsunder lateral low cyclic load and constant axial load was carried out. By comparing the failuremodes and hysteresis curves of the specimens, the influence of each parameter on the bearingcapacity, ductility, hysteretic behavior and energy dissipating capacity was analyzed. The resultsshow that the bearing capacity, ductility and energy dissipating capacity of the strengthened piersare improved significantly. The diagonal shear cracking can be inhibited by the lateral activeconfined stress provided by pre-stressed CFRP belts, and then the failure mechanism of thespecimens strengthened with pre-stressed CFRP belts can be changed from shear to flexure whichis of satisfactory ductility. Compared with the sequence of strengthcning with pre-stressed CFRPbelts at first and then exerting axial load, the sequence of exerting axial load at first will decrease the bearing capacity of the specimens.