钢筋套筒挤压搭接连接叠合次梁-主梁连接节点受力性能试验研究

为研究后浇段设置在次梁端与主梁侧面之间、叠合次梁预制部分纵筋采用套筒挤压搭接连接的叠合次梁-主梁连接节点的受力性能，进行了1个端节点和1个中节点试件在次梁悬臂端竖向荷载作用下的静力试验。研究结果表明：次梁受压、受拉纵筋套筒挤压搭接接头可有效传力，套筒没有出现裂纹，钢筋没有发生滑移；次梁预制混凝土与后浇混凝土结合面未见破坏，次梁的破坏形态为固端一倍梁高范围内类似深梁的斜截面弯曲破坏，可以采用“拉-压杆”模型解释次梁的受力机理、截面应变分布；次梁的实测承载力与《混凝土结构设计规范》正截面受弯承载力预测值的比值平均为1.37，与“拉 压杆”模型承载力计算值的比值平均为1.09。

Experimental study on mechanical behavior of composite RC beam and girder joints with rebars lapping in pressed sleeve

To study the mechanical behavior of composite RC beam-girder joints connected by post-casting section with beam longitudinal rebars lapping in pressed sleeve, static tests of one exterior composite RC beam-girder joint and one interior composite RC beam-girder joint have been carried out. The test results indicate that the lapping pressed sleeve splice can transfer force of the composite RC beam longitudinal rebars effectively with no cracks on the sleeve and no rebar slippage. All specimens fail in a diagonal flexural failure within the range of one beam height, which is similar to the failure mode of deep beams, rather than fail in a flexural failure of the bending beam. The strut-and-tie model of the discontinuity region can explain the failure mode and strain distribution fairly well. The ratio of the measured peak load to the calculated capacity following the formula in the current in force design code is about 1.37, while the ratio of the measured peak load to the calculated capacity following the strut-and-tie model method is about 1.09.