碳纤维布加固震损CFRP筋高韧性纤维混凝土柱抗震性能试验研究

为探究CFRP筋高韧性纤维混凝土柱的抗震性能及可修复性能，以剪跨比和轴压比为变量，设计了6根CFRP筋高韧性纤维混凝土柱，其中3根为不进行加固的对比柱，剩余的3根柱先进行预损伤处理，再用碳纤维布进行加固修复，对上述试件进行低周反复荷载下的抗震性能试验。对试件的破坏形态、滞回特性、刚度退化、延性、综合性能指标以及耗能能力进行研究。结果表明：CFRP筋高韧性纤维混凝土柱表现出明显的多缝开展特征和良好的变形能力；水平荷载下降至峰值荷载的85%，停止加载，试件仍具有较好的完整性，且所有试件均表现出弯曲破坏的特征。轴压比越大，峰值荷载越大，滞回曲线的形状越饱满；剪跨比越大，极限水平位移越大，但峰值荷载越小。加固后试件的累积耗能较未加固试件提高2.0~4.2倍，仍具有良好的耗能能力，说明CFRP筋高韧性纤维混凝土柱具有良好的可修复性，且碳纤维布加固的方法有效可行。

Experimental study on seismic performance of damaged engineered cementitious composite columns reinforced with CFRP bars and strengthened by CFRP sheets

In order to study the seismic behavior and repairing capacity of CFRP reinforced engineered cementitious composite (ECC) columns, six engineered cementitious composite columns reinforced with carbon fiber reinforced plastic bars (CFRP-ECC columns) were designed. Three of the specimens without strengthening were control specimens. The other three specimens were pre-damaged and then strengthened with CFRP sheets. Taking the axial compression ratio and shear span-depth ratio as parameters, this paper presented studies on the seismic behavior of specimens under reversed cyclic load. The failure patterns, hysteretic curve, skeleton curve, stiffness degradation, ductility, comprehensive performance index and energy dissipation capacity of specimens were further studied. The results indicate that CFRP-ECC columns show obvious multiple-cracking behaviors and excellent deformation capacity. After the test is completed, the specimens still have good integrity, and all specimens show the characteristics of flexural failure mode. With the increase of axial compression ratio, the horizontal ultimate load of specimens and the area of hysteresis curve increase. With the increase of shear span-depth ratio, the ultimate horizontal displacement increases, but the horizontal ultimate load of specimens decreases. The accumulated hysteretic energy of the strengthened specimens is 2.0~4.2 times higher than that of the unstrengthened specimens. The strengthened specimens still have great energy dissipation ability, indicating that the CFRP-ECC columns have good recoverability and using CFRP sheets to strengthen such columns is effective and feasible.