CFRP筋黏结型锚具试验研究及实桥应用分析

Experimental Study and Practical Application of Bond-type Anchorages for CFRP Tendons

为了锚固碳纤维增强复合材料(CFRP)筋材,并将其应用于实桥中,提出了一种黏结型锚具,首先采用有限元法分析该锚具的受力性能,再采用试验方法研究该锚具锚固单根CFRP筋的锚固性能;然后利用该锚具制作了5束大吨位试验索,并测试其极限承载力,同时研究黏结型锚具的黏结强度、锚具效率系数、持荷效应等;最后将该黏结型锚具应用于试验桥中。研究结果表明:平均黏结应力随黏结长度的增大而减小,但是锚具的极限承载力提高;锚具的效率系数达到93%以上,满足试验桥设计要求;树脂灌注型锚具的大部分蠕变变形在加载后较短的时间内发生;试验桥拉索测试时各根筋材受力均匀性较好,且持荷一定时间后测试的应力下降较小。

In order to anchor carbon fiber reinforced polymer（CFRP）tendons and apply them to a real bridge,a new bond-type anchorage was designed.Firstly,the mechanical performances of the anchorage were analyzed using finite element method（FEM）.Secondly,the bond performances of the anchorage anchoring single CFRP tendon were analyzed using experimental method.Then,five CFRP cables were fabricated with the anchorage and the ultimate bearing capacity was tested.At the same time,bond strength,efficiency coefficient and sustained loading effect of bond-type anchorage were discussed.Finally,the bond-type anchorage was applied to an experimental bridge.The results show that the mean bond stress decreases with the increase of bonded length,even though the ultimate bearing capacity increases.The anchorage efficiency coefficient is equal to or greater than 93%,which satisfies the design requirement for the experimental bridge.Most of the creep deformations of resin in the anchorage occur within a short time after loading.The uniformity of the tendon stresses within each cable system is good and the stresses decrease very little after sustained loading for a certain time.