不同钢筋斜伸角度下叠合板拼缝试验研究

Experimental study on laminated slabs connected with different angles of steel bars

为了对预应力叠合楼板非预应力方向板侧拼缝处通过预制底板钢筋斜伸构造达到传力作用,实现叠合板的双向受力,通过对预制底板钢筋不同斜伸角度的拼缝叠合板进行静力加载试验,分析了不同角度的大跨度预应力叠合板裂缝开展情况、挠度、钢筋应力以及受弯承载力性能,并与现浇板进行了对比。试验结果表明:叠合板均为弯曲破坏特征;叠合板与现浇板相比较,叠合板裂缝宽度发展较快,其中DH-60、DH-75在试验过程中裂缝条数较少,裂缝宽度发展更为明显;预制层端部钢筋斜向角度对板承载能力和变形能力有一定的影响,钢筋斜向60°和75°伸出板侧拼缝要比斜向30°和45°的板承载能力和变形能力差;预制层端部钢筋斜向30°~60°的板具备较好的承载能力,表明拼缝通过合理的构造措施能够满足叠合板抗弯承载力要求,为预应力混凝土叠合楼板拼缝后双向受力研究提供参考。

In order to study the mechanical behavior of connections between slabs with different inclined angles of steel bars in the non⁃prestressing direction of prestressed laminated slabs,and the two⁃way force of slabs is achieved.The large⁃span prestressed laminated slabs connected with different inclined angles of steel bars under the static loading are studied.The crack development,deflection,reinforcement stress and bending capacity of it are analyzed,and compared with a cast⁃in⁃place slab.The test results show that the slabs belong to flexural failure mode;the crack width of the laminated slabs develops faster than that of the cast⁃in⁃place slab,and the number of cracks in the laminated slabs connected with 60°and 75°steel bars is less,and the crack width develops more obviously during the test;the inclined angles of the steel bars at the end of the precast concrete have an influence on the bearing capacity and deformation capacity of the slabs,and the slabs connected with 60°and 75°steel bars are worse than those with 30°and 45°;the laminated slabs connected with the inclined angles of the steel bars from 30°to 60°have better bearing capacity,which indicates that the connection can meet the bending bearing capacity requirements of the slabs through reasonable structural measures.It provides reference for the study on prestressed laminated slabs.