表层嵌贴碳纤维筋加固钢筋混凝土梁受弯性能试验研究

Experimental study on mechanical behavior of reinforced concrete beams strengthened with near surface mounted CFRP rods

表层嵌贴碳纤维筋加固法(简称NSM法)是目前碳纤维加固的最新方法。为研究表层嵌贴螺纹碳纤维筋的粘结性能,首先完成了2组6个拉拔试件的粘结性能试验,对采用环氧树脂胶配置的环氧树脂砂浆的粘结性能进行对比研究。通过对3根钢筋混凝土简支梁受弯性能试验研究,分析了附加锚固件对加固后钢筋混凝土梁受力性能的影响。在试验过程中,对加固试件裂缝开展、破坏形态和碳纤维筋应变发展情况进行了详细观测。试验研究结果表明,表层嵌贴螺纹碳纤维筋受力较为复杂,应力传递不是连续均匀的;附加锚固件对加固后钢筋混凝土梁的开裂荷载、屈服荷载无影响,但对极限荷载提高作用较明显。

The near surface mounted(NSM) carbon fiber-reinforced polymer(CFRP)(which usually be abbreviated as CFRP-NSM method) was a new strengthening technology for reinforced concrete(RC) structures,in which the CFRP rods or strips was mounted in the groves by bond material,and the CFRP rods or strips could work together with old RC members,and then the RC members were strengthened.Firstly,6 specimens in two groups for pull-out test were conducted to study the bond performance of the CFRP rods with the Epoxy mortar material which made by the old or new Epoxy resin.And furthermore,3 RC simple supported beams strengthened with the NSM CFRP rods were tested,and the effect of additional anchorage on the mechanical behavior of reinforced concrete beam was especially studied.During the experiment process,the failure modes,strains of CFRP rods which mounted in the RC beams and the cracking type were studied in detail.From the experimental study,it could be found that the RC simple supported beams strengthened with the CFRP-NSM method showed more complex power.The additional anchorage had no effect on cracking load,stiffness and yield load,but on the ultimate load was more significantly.