碳纤维加固混凝土梁界面黏结剪应力的参数分析

Parameterized Analysis of Interfacial Bonded Shear Stress of RC Beams Strengthened with CFRP Sheets

基于弹性理论建立了碳纤维加固钢筋混凝土梁的界面剪应力模型,研究了四点弯曲情况下的界面黏结胶层剪应力的分布规律,明确了改变各相关参数对界面黏结剪应力的影响程度。计算结果表明,界面黏结剪应力最大值位于碳纤维的黏结端部,并且剪应力随着距离的增加呈现出非线性递减趋势,当距离超过一定长度后,碳纤维与混凝土界面间的黏结剪应力值降为很小,其值基本接近于零,因此在实际工程中应注意端部的锚固。同时发现增加梁高度、胶层厚度可以降低碳纤维与混凝土界面黏结剪应力值;增加碳纤维粘贴层数和碳纤维端部距离支点的距离可以增大碳纤维与混凝土界面黏结剪应力值,此规律应在实际加固工程中加以利用。

On the basis of the elastic theory, the model of interfacial shear stress between the CFRP and concrete is established in the paper. The distribution law of shear stress between CFRP and concrete is studied, and the influence degree of some parameters on the interracial shear stress is made clearly. The results show that the maximum interracial shear stress locates at the bonded end of CFRP, the interracial shear stress decreased to about 0 MPa with the increasing of distance, so the end anchorage will be paid more attention in the actual engineering. At the same time increasing the beam height and adhesive thickness can decrease the interracial shear stress between CFRP and concrete, but increasing the adhesive layer number of CFRP and the distance between the end CFRP and bearing can increase the interfacial shear stress between CFRP and concrete, and the law must be used in the actual engineering.