单缝密拼钢筋混凝土叠合板受弯性能试验研究

通过10块简支板的静力加载试验，对单缝密拼钢筋混凝土叠合板的破坏形态、刚度、裂缝和承载力进行了研究，并分析了桁架钢筋叠合板密拼缝的传力机理以及桁架钢筋与纵向受力钢筋的定量关系。结果表明：单缝密拼叠合板易在拼缝处发生沿叠合面的撕裂破坏，且其正截面受弯承载力和平均抗弯刚度均低于整浇板；在拼缝处设置桁架钢筋可以有效控制叠合面的撕裂破坏，并提高叠合板垂直于拼缝方向的刚度和承载力；桁架钢筋到拼缝距离等于板厚的试件，未发生拼缝处的叠合面撕裂破坏，其正截面受弯承载力比整浇板试件低6%，但比计算值大9%~18%。结合试验研究成果和国内外相关标准，提出了双向叠合板密拼拼缝的设计建议与构造要求。

Experimental research on flexural behavior of reinforced concrete composite slab connected without gap

Ten simply supported slabs were tested under static loading to investigate the failure mode, stiffness, crack and bearing capacity of reinforced concrete composite slabs connected without gap. The tie-and-strut model of indirect lap of longitudinal reinforcement was used to analyze the quantitative relationship between lattice girder and longitudinal reinforcement. The research results indicated that the composite slab connected without gaps can be split easily along the interface between the old and new concretes, and that the bearing capacity of normal section and average stiffness were lower than those of cast-in-place slab. It was found that setting lattice girders across the seam could effectively control splitting failure and enhance the stiffness and bearing capacity perpendicular to the joint. When the distance between the lattice girder and the seam was equal to the thickness of the slab, splitting failure of specimens did not occur along the interface between the old and new concretes, and the bearing capacity of normal section was 6% lower than that of cast-in-place slab but 9%-18% larger than the calculated value. Design suggestions and construction requirements of the two-way composite slab connected without gap were proposed, based on the research results and the relevant national and international standards.