混凝土梁侧面粘贴CFRP布的结构加固性能的试验研究

研究采用在混凝土构件侧面粘贴碳纤维布这种新形式加固受弯构件的受力性能，试验研究共设计了4根少筋梁，试验时，先通过2个对称的集中荷载将梁预加载至纯弯段出现一道主裂缝并失效，然后，卸载并用碳纤维布粘贴于梁侧面受拉区予以加强，待粘贴树脂固化后，再重新加载至梁的极限荷载，试验重点研究了该种加固梁的极限荷载，变形，开裂和碳纤维布粘贴形式对加固效果的影响，试验结果表明，该种加固梁不但承载力提高显著，而且具有很好的延性，消除了原来在梁底粘贴碳纤维加固梁在极限状态时因碳纤维布突然断裂而出现的脆性破坏现象，基于试验研究结果，导出了这种加固梁承载力的实用计算方法，该方法计算精度较好且偏于安全，可直接应用于实际加固工程，特别是当构件底面有管道等障碍物时。

Experimental study on the behavior of the strengthened RC beam side-bonded with CFRP sheets

The behavior of the flexural RC member bonded with carbon fiber reinforced polymer(CFRP) sheet on its vertical sides was first investigated by the authors recently. A total of four under reinforced concrete beams were elaborately devised and cast. Each specimen was pre loaded under two symmetrical concentrated loads to occur a crack and failure, then unloaded and strengthened by bonding CFRP sheet on its side tensile faces. After proper curing, the specimens loaded again up to ultimate stage. The ultimate load, deformation, cracking, CFRP bonding scheme for the specimens were examined. The experimental result shows that this kind of retrofitted beam eliminates the occurrence of brittle fracture and has significant strength gain. Based on this study a practical design method is proposed, which has good agreement with the experimental results and trends to be safe. This method is especially applicable for the structure when there are some obstructions underneath.