组合封闭式箍筋双筋混凝土梁受弯性能试验研究

Bending Behavior of RC Beams with Compression Reinforcement and Assembled Stirrups

组合封闭式箍筋的使用是预制装配整体式混凝土结构关键技术之一。试验研究采用组合封闭式箍筋的双筋混凝土梁受弯性能。试验分两批:第一批试验包括13根一次浇筑梁试件,目的是考察不同箍筋形式梁受力性能差异;第二批6根叠合梁试件,考察足尺和叠合梁受弯力学性能。其他研究参数还包括受压纵筋和箍筋间距。研究表明,对于一次或叠合浇筑的双筋混凝土梁,组合封闭式箍筋可以对受压纵筋提供有效侧向约束,受压纵筋没有在梁破坏之前失稳。在本研究参数范围内,配置组合封闭式箍筋和传统封闭式箍筋双筋梁的受弯性能没有区别,可采用相同的计算方法预测受弯性能。

The application of assembled stirrups is one of the key techniques for prefabricated assembled inte-gral RC structures.This paper presents the experimental studies on the bending behavior of RC beams with compression reinforcement and assembled stirrups.The test program was divided to two groups.In the first group,13 beam specimens were casted at the same time to investigate the bending behavior regarding different stirrup forms.In the second group,sixs uperposed beams were tested to investigate the bending behavior re-garding large dimensions of the specimens.Other considered study parameters included compression reinforce-ments and stirrup intervals.It was found that the assembled stirrups can provide sufficient lateral restraint to the compression reinforcement in RC beams.The compression reinforcements do not lose the stability prior to the failure of the specimens.No differences were observed between RC beams with assembled stirrups and those with traditional stirrups.The analytical method,which was common used for the prediction of the ben-ding behavior of RC beams with traditional stirrups,was verified to be appropriate for the prediction of that with assembled stirrups.