FRP嵌入式加固带裂缝混凝土梁力学性能研究

Study on mechanical properties of FRP embedded reinforced concrete beams

采用两种纤维增强复合材料(CFRP和BFRP)嵌入法(NSM)加固预制裂缝的混凝土梁,进行三点弯曲试验,探究其对混凝土裂缝的控制作用及其与混凝土界面黏结性能。分析了临界状态出现的机理,比较了两种FRP筋加固效果。结果表明,BFRP嵌入法加固梁的极限荷载高于CFRP嵌入法加固的情况,且延性也高于后者;破坏形式主要为是沿预制裂缝的弯曲破坏;但随着缝高比的增大,个别梁出现弯剪斜裂缝;界面破坏均发生在FRP筋与环氧树脂胶界面,混凝土与胶界面未发生黏结破坏。

Two kinds of fiber reinforced polymer(CFRP and BFRP)composite embedding method(NSM)were used to reinforce the precast cracked concrete beam,and the three-point bending test was carried out to explore its bonding performance.The first peak load mechanism and the causes of different failure modes were analyzed,and the reinforcement effects of the two FRP bars were compared.It is found that the BFRP embedding method is stronger than the CFRP embedding method.The CFRP embedding method is better than the BFRP embedding method.The main failure mode is the bending failure along the prefabricated crack,but with the seam.The increase of the height ratio causes the shear failure of the oblique crack.The damage is caused by the slip between the FRP rib and the binder,and there is no bond between the binder and the concrete.The interface peeling damage.