粘贴纤维布加固RC梁的受弯裂缝计算方法

针对目前关于粘贴纤维布(FRP)限制钢筋混凝土(RC)梁裂缝开裂的作用缺乏理论探讨和定量分析的问题,根据混凝土裂缝开裂机理建立了粘贴纤维布加固梁的裂缝开裂全过程表达式,在5片粘贴纤维布加固的RC简支T型梁试验中定量研究了不同受力阶段下的裂缝宽度和裂缝间距,理论分析和试验研究都考虑了初始荷载对裂缝开裂的影响。分析表明:纤维布粘结应力是裂缝间距和宽度减小的主要原因,粘贴纤维布加固后梁的裂缝开裂分为两个阶段。最后,提出了粘贴纤维布加固RC梁的受弯裂缝宽度计算方法。

Calculation Method on Bending Crack in RC Beams Strengthened with FRP

Aimed at the problem of less theoretical discussion and quantitative analysis on the restriction of fiber-reinforced polymer(FRP) to the crack of reinforced concrete(RC) beams,according to concrete crack theory,the expression of the cracking process of RC beams strengthened with FRP was founded.Based on the experiment of five model T-beams strengthened with FRP,the crack width and spacing in different load levels were quantitatively analyzed.The effect of initial load to crack was considered both in the theoretical study and the experimental study.The result shows that the bond stress of FRP is the main cause to lessening crack width and spacing,and the cracking process of the strengthened RC beams can be divided into two phases.Finally,an improved method of calculating crack width of RC beams strengthened with FRP was suggested.