局部外包方钢管连接混凝土构件工作性能试验研究

Experimental research on connection performance of concrete member using local square steel tubes

设计了6个局部外包方钢管连接的装配整体式混凝土试件和1个现浇对比试件.通过单向反复加载试验,测试了结头处预制构件与方钢管之间的粘结滑移变化规律,观测了装配整体式构件受力—变形—裂缝—屈服—破坏的全过程,分析了装配整体式构件的破坏特征、滑移曲线、挠度曲线和位移延性等.研究表明:荷载作用下,带栓筋局部外包方钢管连接节点处,方钢管与预制混凝土构件的滑移量很小,整个装配构件挠度发展缓慢,抗弯承载力与现浇构件相差无几,极限荷载下跨中挠度比现浇构件还小;同时,增加方钢管的长度和厚度在一定范围内能提高装配整体式构件的抗弯承载力,减少构件跨中挠度以及方钢管与预制混凝土构件之间的相对滑移量;局部外包纯方钢管连接形式的装配构件节点处,方钢管与预制混凝凝土构件之间的相对滑移较大,承载力比现浇构件低,挠度发展速度较快,破坏时整个构件的跨中挠度大.建议在实际工程中使用带栓筋局部外包方钢管连接方式.

Six prefabricated connection specimen and one ordinary connection specimen were designed and constructed by using square steel tube.By one-way repeated load testing,the slip between the precast plate and the square steel tube in the junction was researched.The whole process of deforming-cracking-yielding-failure was observed and the damage character,slip curve,deflection curve and the displacement ductility were analyzed.Test results showed that the slips of the prefabricated specimen by using square steel tube with bolt tendons were small and the deflection developed slowly,and even the final deflection value was smaller than the ordinary specimen.At the same time,the flexural capacity of these specimens was nearly the same as the ordinary specimen and increasing the length and the thickness of the square steel tube could constrain the develop of the slip and the deflection in certain area.Meanwhile,the slip of the prefabricated specimen connected only by square steel tube was bigger and its barring capacity was lower than the ordinary specimen.It is suggested that it is better to use square steel tube with bolt tendons in practical engineering.