钢筋套筒灌浆搭接连接的预制框架柱抗震试验

为研究竖向钢筋采用新型套筒灌浆搭接连接的预制柱的抗震性能,在已研发的Ⅰ、Ⅲ型套筒灌浆搭接接头的基础上进行了1个现浇柱、2个预制柱的拟静力试验.试验现象如下:现浇柱的初始水平裂缝出现在根部,预制柱由于套筒约束了混凝土的竖向应变,初始水平裂缝出现在套筒顶面;极限状态下现浇柱压碎区段长,预制柱压碎区段短.试验结果表明:预制柱的开裂、屈服荷载略大于现浇柱,极限荷载高于现浇柱;预制柱的开裂、屈服位移与现浇柱相近,极限荷载时位移、极限位移、延性系数大于现浇柱.由于预制柱根部套筒范围内箍筋加密,预制柱的耗能能力略优于现浇柱.Ⅰ、Ⅲ型套筒上下方钢筋应变基本一致,表明Ⅰ、Ⅲ型套筒在预制柱中能够很好的传递钢筋应力.

Experimental Study on Seismic Behavior of Precast Frame Column with Vertical Reinforcement Spliced by Grouted Sleeve Lapping Connector

In order to study the aseismic performance of the precast column connected with the new type of slurry anchor connection, a cast-in-place columns and two prefabricated column specimens, in which longitudinal reinforcement were connected by type I and III grouted sleeve lapping connector respectively, were designed for quasi-static test on the basis of the type I and III sleeve joint connection. The test phenomena show that the initial horizontal cracks of the cast-in-place column appear at the root. Because the vertical strain of the concrete is restrained by the sleeve, the initial horizontal cracks of the precast column appear on the top of the sleeve. In the limit state, the crushed part of the cast-in-place columns is long and the crushed part of the precast columns is short. The test results show that the cracking load and yield load of the precast column are slightly larger than the cast-in-place column, and the ultimate load of the precast column is higher. The cracking load, yield load of the two different types are almost the same, but the displacement under the ultimate load, ultimate displacement and ductility coefficient of the precast column are larger. Due to the stirrup encryption in the range of the sleeve of the precast column, the energy dissipation of the precast column is slightly better than the cast-in-place column. The strain of steel bar on the upper and lower parts of type I and type III sleeve is basically the same, so both of them can perform well in transferring the stress.