Research On The Horizontal Shear-bond Properties Of Lightweight Aggregate Composite Slabs

As a new type of composite structure, cold-formed steel deck and lightweight aggregate concrete composite slab is characterized by the advantages of high bearing capability and rigidity and excellent anti-seismic property, which has brought about remarkable economic benefits to the society. The adoption of the composite slab in building construction could expedite the project progress and provide space for pipelines without damaging the structure. For the above reasons, it has been widely used in steel structure and composite structure buildings in recent years.Compared with common concrete, lightweight aggregate concrete is advantaged by light self-weight, high strength and good heat-insulating property, which is properly used in high-rise buildings. Meanwhile, the lightweight aggregate concrete can be produced by industry wastes, such as coal gangue, pulverized fuel ash and so on. So if the common concrete of the composite slab is substituted by lightweight aggregate concrete, the slab could not only keep its advantages but also reduce its self-weight, which is significant to lower the building cost. At the same time, the environmental pollution caused by industry wastes could be solved to some degree.At present, the research on composite slabs is focused mostly on mechanical property of common concrete composite slabs, while little attention has been paid to lightweight aggregate concrete composite slabs, and the design method has not been stipulated clearly in the building code.Based on the general review of the home and abroad research results of mechanical property and failure mechanism of cold-formed steel deck and concrete composite slabs, a test for longitudinal shear capacity of cold-formed steel deck and lightweight aggregate concrete composite slabs has been designed and implemented, in which six full-scale composite slabs have been made with YX-76-344-688 steel deck and haydite concrete, and in which two-point symmetry loading approach has been adopted with simple supports. In this paper, the influence of the end studs and transverse reinforcement to the shear capacity is mainly considered, and the horizontal shear-bond properties and shear failure reason of the slabs are discussed in detail according to the measurement results of steel and concrete strains, relative slip and the defection of the slabs. Finally, a formula is recommended to calculate the horizontal shear-bond resistance in the light of the linear regression analysis of the test data. The conclusion can be used for further research on the lightweight aggregate composite slabs as a reference.