预应力碳纤维布加固混凝土板受弯承载力实用方法研究

Study on practical method of flexural bearing capacity of concrete slabs strengthened with prestressed CFRP sheets

提出了一种新型实用碳纤维布加固系统,包含首次提出的碳纤维布环氧树脂楔形夹持体夹具、张拉设备和碳纤维布薄层钢板锚具。试验表明,环氧树脂楔形夹持体夹具夹持力强,应力损失低,施工安全,现场安装方便,且易于在工厂加工制作,适合于实际工程批量应用;张拉设备轻便,易于安装,不受构件支承条件影响。采用该新型实用碳纤维布加固系统对混凝土薄板进行的验证性加固试验表明,张拉设备方便适用,工艺流畅;预应力碳纤维布加固后构件工作性能明显改善,开裂前的弹性极限荷载达到未加固对比试件及普通粘贴碳纤维布加固试件的4倍;预应力碳纤维布加固试件的极限承载力比未加固试件提高103%,比普通粘贴碳纤维布加固试件提高32%,承载力明显提高。碳纤维布直至断裂也未从薄层钢板锚具中滑出,验证了其良好的锚固性能。

A new practical strengthening system of prestressed CFRP sheets was proposed,which consisted of the firstly presented epoxy resin wedge clamps for CFRP sheets,tension equipment and double-thin-layer steel plate anchorages. Test results show that the epoxy resin wedge clamp has advantages including strong clamping force,low stress loss,safe construction,convenient on-site installation,and easy processing in the factory. It is suitable for practical engineering batch application. The tension equipment is light and easy to install,and is not affected by component support conditions. The verification strengthening test of the concrete thin plate by the new practical strengthening system of prestressed CFRP sheets shows that the tension equipment is convenient and applicable,and the process is smooth;the elastic ultimate load of the test specimen strengthened with prestressed CFRP sheet before cracking reaches 4 times of the non-strengthened test specimen and the ordinary CFRP paste-strengthened test specimen;the ultimate bearing capacity of the test specimen strengthened with prestressed CFRP sheet is 103% higher than that of the non-strengthened test specimens,32% higher than that of the ordinary CFRP paste-strengthened test specimens,and the bearing capacity is significantly improved. The CFRP sheets did not slip out of the double-thin-layer steel plate anchorages until it broke,which proved its good anchoring performance.