带纤维锚具的碳纤维复材与混凝土界面黏结性能试验研究

AN EXPERIMENTAL STUDY ON BOND BEHAVIOR BETWEEN CONCRETE AND CFRP WITH FIBER ANCHOR

为了深入理解纤维锚具对纤维增强复合材料(简称"复材")与混凝土界面黏结性能的影响,对梁底面黏结碳纤维复材的13根预置裂缝梁进行了试验,研究了锚具样式、锚具纤维用量及锚具分布三个因素对碳纤维复材与混凝土界面黏结性能的影响。试验结果表明:不同锚具样式中刚性锚具的锚固效果优于柔性锚具,且前者可更有效提高碳纤维复材的材料利用率;增大锚具纤维用量及布置多个锚具均可提高碳纤维复材与混凝土的界面黏结能力,有效约束裂缝张开位移;锚具布置位置距碳纤维复材自由端过近将影响锚具和碳纤维复材与混凝土黏结界面的协同受力,降低锚具的锚固效果,因此该距离不宜小于碳纤维复材的有效黏结长度。

In this study, 13 beams with pre-set cracks were tested with CFRP strips bonded to the beam soffit to explore the effects of fiber anchors on the bond behavior of CFRP-to-concrete bonded interface （referred to as ＂the interface＂ for simplicity hereafter）. The investigated parameters included the anchor type, fiber content and distribution of anchors. The test results showed that the anchoring effect of rigid anchor was superior to that of flexible anchor, as a result, the application of rigid anchor significantly increased the maximum stress of CFRP and the efficiency of applying CFRP. The test results also showed that increasing fiber content of anchor and/or installing multiple anchors could effectively improve the bond strength of the interface and constrain the opening of pre-crack. The results also suggested that to achieve an optimized beneficial interaction effect between the bond of the CFRP-to- concrete interface and the anchoring effect of the fiber anchor, the distance between the free end of CFRP and the adjacent fiber anchor should not be shorter than the effective bond length of CFRP.