碳纤维布加固混凝土框架在竖向荷载下的试验研究

为研究碳纤维布加固方式对框架结构性能的影响,按1∶3缩尺模型设计了用碳纤维布加固损伤钢筋混凝土框架结构的试验试件,进行了竖向荷载作用下的试验研究分析.试验结果表明,对损伤混凝土结构较大裂缝进行灌胶密闭和粘贴间距较小的U型箍能够有效抑制裂缝开展;梁底粘贴碳纤维布在粘结锚固满足的情况下,不仅能够有效延缓钢筋的屈服,而且可以大幅度提高梁的极限抗弯承载力.由于碳纤维布的约束作用,加固后梁的截面抗弯刚度有所提高.碳纤维布加固后的梁的拉力由钢筋和碳纤维布共同承担,钢筋屈服后碳纤维布的作用明显增大,承担其主要拉力,为防止碳纤维布突然拉断,需考虑其有效利用率问题.

Experimental Investigation of Damaged RC Frame Structure Strengthened with CFRP under the Vertical Load

The test model of damaged RC frame structure strengthened at CFRP was designed at the scale 1:3 in order to study how the performance of the RC frame structure will be affected by the strengthening method.The experiment under the vertical loads was carried out.The test results indicate that the cracks are restrained because the damaged cracks were filled into the structural adhesion and plastered the close-spaced "U" shape CFRP stirrup.At same time,the yielding load and ultimate flexural capacity of the damaged RC frame structure strengthened with CFRP are increased greatly,and the flexural rigidity was better. Under the vertical loads,the tension is taken on both CFRP and steel bar.The tension is taken on mainly by CFRP after the steel bar is drawn on ultimate strength,but the whole strength of CFRP cannot be fulfilled.