混凝土中黏结型锚栓剪切试验方法

Shear test methods of bonded anchor bolts in concrete

针对单独锚栓剪切试验方法(SSTM)存在的缺陷,提出2套在加载板尾部配置辅助锚栓的双锚栓剪切试验方法(DSTM).总计6个直径规格、90个锚栓的比对剪切试验表明,单独锚栓剪切试验获得的承载力低于双锚栓剪切试验获得的承载力,但均能达到以0.6倍锚栓杆体抗拉强度表示的理论剪切承载力的水平;单独锚栓试验加载板的转动导致剪力-位移实测曲线存在明显的离散性;在双锚栓试验中,对辅助锚栓施加约2.0 kN的预紧力,就能在加载板转动约束体系中建立有效的连接,借助辅助锚栓的拉伸刚度有效限制加载板的转动,显著降低剪力-位移试验曲线的离散性.2套双锚栓剪切试验方法获得的试验结果具有一致性,作为辅助锚栓使用时承担拉力的历史不会影响其剪切性能.

Two sets of dual anchors shear test methods(DSTMs)were proposed by considering the shortcomings of single anchor shear test method(SSTM).An auxiliary anchor was provided at the rear end of loading plate.Test results of 90 anchor bolts in six diameters show that the shear capacity obtained from SSTM is lower than that from DSTM,but all of them being larger than the theoretical values expressed in 0.6 times the shaft tensile fracture strength.As a result of tilting of loading plate toward the pull force,measured shear-displacement curves from SSTM had higher stochastic characteristics than those from DSTMs.Positive connection would be reached in the tilting-restraining system by exerting about 2.0 kN pre-tension force in auxiliary anchor,and effective control of loading plate tilting would be reached by virtue of the tensile rigidity of auxiliary anchor,greatly reducing in the scattering of shear-displacement curves from DSTM.Determined consistency exists between test results from both of the two sets of DSTMs system,indicating that the tension history of auxiliary anchor would not adversely affect its shear properties.