设计了一种CFRP筋夹板式锚具,通过对40个CFRP筋.锚具组装件的拉拔试验,研究了锚固长度、螺栓预紧力、螺栓数量和CFRP筋表面处理等对锚具锚固性能的影响。试验结果表明:试件的破坏形态包括CFRP筋的滑移、断裂和拉脱三种,试件达到极限荷载时的滑移量较小。增加锚固长度、螺栓总预紧力、螺栓数量以及对CFRP筋表面打磨处理均可在一定范围内提高锚具试件的极限荷载。通过合理控制上述参数,可以使锚具发挥良好的锚固性能,满足实际使用要求。该文给出了CFRP筋夹板式锚具合理的构造和螺栓预紧力值。在试验研究基础上,分析了CFRP筋夹板式锚具的锚固作用机理,建立考虑锚固长度、螺栓预紧力和螺栓数量的CFRP筋一锚具界面平均摩擦系数模型,并提出夹板式锚具的极限荷载计算公式,与试验结果吻合良好,具有较好的适用性。
A series of 40 pull-out tests were carried out to study the anchorage performance of a new type of clamping anchor for CFRP rods. The various variables included the bonded length, the pre-tightening forces and number of bolts, and the surface treatment of CFRP rod. There were three types of failure modes observed in the tests, namely fracture, slip and pullout of CFRP rod, respectively. Slight slip was measured when the ultimate load of specimen was reached. Test results show that increasing the bonded length, pre-tightening forces or number of bolts leads to a higher ultimate load, and so does rod-surface rubbing. Suitable size of the clamping anchor and pre-tightening forces of bolts are proposed. The anchorage mechanism of the clamping anchor is analyzed, and a model to predict the ultimate capacity of specimen is put forward based on the test results. The calculated results are in good agreement with the test ones.