新型带可拆桁架肋叠合双向楼盖试验

为了研究新型带可拆桁架肋叠合双向楼盖的力学性能,进行了2块不同配筋形式新型叠合双向板和1块现浇双向板的静载试验,对新型叠合双向板的施工阶段进行了模拟加载试验,在未设支撑的情况下,测试了预制板在施工荷载作用下的挠度,并对比分析了试件在使用阶段的裂缝分布、破坏形态、刚度变化、挠曲变形、开裂荷载、受弯承载力、整体工作受力性能等基本力学性能。结果表明:预制板在施工阶段的挠度限值满足规范要求,桁架肋在新型叠合双向板的施工阶段起支撑作用,承担施工荷载,在施工过程中可不另设支撑; 新型叠合双向板与现浇双向板的裂缝分布、破坏形态、承载能力基本相同,开裂荷载较现浇双向板提前; 与现浇双向板相比,新型叠合双向板中叠合层和预埋件在一定程度上削弱了楼板的整体性,但影响不大; 在配筋面积基本相同的情况下,预制板内采用细钢筋可以提高叠合双向板的抗裂性能; 在使用阶段,自然粗糙面的构造措施能够较好地保证叠合面的抗剪能力,在弹性受力阶段预制板和后浇层能够协同工作,具有良好的整体性。

Experimental on New Type of Two-way Composite Floor Slab with Recycling Truss Ribs

In order to study the mechanical property of new type of two way composite floor with recycling truss ribs, the static load tests of two new composite bidirectional plates with different reinforcements and one cast-in-place bidirectional plate were carried out. The simulated loading test was carried out for the new type of composite bidirectional slab in the construction stage. The deflection of prefabricated slab under construction load was tested without support. The basic mechanical properties such as crack distribution, failure mode, stiffness change, deflection, cracking load, bending capacity and overall working performance were compared and analyzed. The results show that the deflection limit of prefabricated slab in construction stage meets the requirements of specifications. The truss ribs play a supporting role in the construction stage of the new composite bidirectional slab, and the truss ribs bear the construction load. The crack distribution, failure mode and bearing capacity of the new composite bidirectional slab and the cast-in-place bidirectional slab are basically the same, and the cracking load is earlier than that of the cast-in-place bidirectional slab. Compared with the cast-in-place bidirectional slab, the existence of laminated layer and embedded parts in the new composite bidirectional slab weakens the integrity of the slab to some extent, but the influence is relatively small. In the case that the area of reinforcement is basically the same, the use of fine reinforcement in the prefabricated plate can improve the anti-cracking performance of the composite bi-directional plate. In the use stage, the structure measures of the natural rough surface can ensure the shear resistance of the composite surface. In the elastic stress stage, the precast plate and the post-cast layer can work together and have good integrity.