弯剪受力下化学植筋式群锚连接试验研究

Experimental study on behavior of bonded-in reinforcement anchorage group under combined of moment and shear loading

通过五个化学植筋式型钢-混凝土后锚固连接节点的弯剪受力试验,研究了该类连接节点的极限承载力、破坏形态和内力分布等问题。试验结果表明该类节点均表现为钢筋破坏,破坏前兆明显,即受拉侧锚板被拉离基材表面。仅钢筋周围混凝土发生小锥体损坏,其它位置无明显开裂。弯矩对连接承载力起控制作用,植筋埋深15d以上时可以保证钢筋充分发挥强度,增加植筋数量对提高后锚固连接件承载力效果显著,内力沿钢筋长度的分布在屈服前基本为线性变化,破坏时前半段钢筋可达到屈服,而钢筋末端的应变很小。

Five steel-to-concrete connections with post-installed reinforcement under eccentric shear loading were tested and static performance of ultimate load capacity,failure mode,strain distribution along reinforcement length were investigated.Experimental results show that anchorage failure is governed by yield and fracture of reinforcement in all specimens and adequate displacement prior to failure in the tension zone of base plate representing a ductile design.Slight concrete cone failure occurred near reinforcement and no visible crack was identified in other portion of concrete surface.The results are used to draw conclusion that the strength of connection is dominated by moment.The reinforcements in the tension zone with embedment depth of 15d can be assumed to develop their full tensile strength for moment resistance.The load capacity of connection would be dramatically improved by adding the number of reinforcements.Strain is linearly distributed along reinforcement length before yield.Under limited load the front portion of reinforcement reached their yield strength while the end part remained little strain.