FRP-螺栓联合加固RC梁受剪承载能力试验研究

Experimental study on RC beams strengthened in shear with hybrid bonding of FRP

为了明确FRP-螺栓联合加固技术(hybrid bonded fiber reinforced polymer,HB-FRP)的抗剪加固效果,结合在役钢筋混凝土桥梁的损伤特点,对表面粘贴FRP加固(externally bonded fiber reinforced polymer,EB-FRP)与HB-FRP两种加固技术进行了详细的室内对比试验,对完整和预裂梁的试验结果进行了分析比较,研究了预裂度和不同FRP条带间距对HB-FRP效果的影响。试验结果表明HB-FRP是一种更可靠的桥梁加固技术,螺栓预紧锚固FRP能够很好地抑制FRP在混凝土表面的剥离,提高FRP与混凝土表面之间黏结力,限制FRP滑移,提高了斜截面的抗剪承载能力,为HB-FRP在桥梁加固维修中的应用提供了可靠依据。

To definitude the effect of FRP-bolt strengthening technology,and also on the basis of the destructive characteristics of aging RC beam bridges,interior contrast tests of FRP surface adhesion and FRP-bolt hybrid boding were conducted to examine the strengthening effect on RC beams in shear.The results of the EB-FRP and HB-FRP were compared.In particular,the influence of pre-cracking level and FRP strip spacing on RC beams strengthened in shear with the hybrid bonding of FRP were assessed.The experimental results show that the hybrid bonding of FRP is a more reliable strengthening technique and which can improve the shear capacity of beams.The new mechanical fastening technique does not rely on bearings to transmit the interfacial shear,but instead increases the interfacial bond by resisting the separation of the FRP laminate from the concrete substrate by the bolt pretension.This study helps to direct the design and the construction of the HB-FRP.