Study Of Basic Structure And Mechanical Properties Of Thin-walled Steel Embedded Lightweight Composite Floor

Thin-walled steel embedded lightweight composite floor is a new type of composite floor.The main construction features are: The thin-walled steel beam skeleton is embedded in lightweight concrete,then make it large-size precast slabs.The precast slabs are connected by overhanging beam of thin-walled steel beam through connectors.So far,there is no relevant study for such composite floor.Therefore,it is necessary to do some related research on bearing mechanism of thin-walled steel embedded lightweight composite floor.When at room temperature and under concentrated load,the deformation resistance,failure form and failure mechanism of thin-walled steel embedded lightweight aggregate concrete composite floor are studied and related parameters are analyzed.The main parameters are: size and thickness of precast composite floor,span of connected composite floor,arrangement and form of reinforcement in single precast slab,design and loading mode of connecting part composite floor.Based on static load tests,effect of above construction parameters and relative factors on mechanical properties was studied,and some selected composite floors were simulated using ANSYS.The results show that the composite floor has high bearing capacity and deformation resistance ability,and the embedded reinforcement and steel wire mesh can effectively enhance the bearing capacity and stiffness of the composite floors.The failure of the composite floor without upper post pouring mortar is due to stringer local buckling of the embedded thin-walled steel beam in midspan.It was seen that the upper post pouring mortar can enhance the plasticity and bearing capacity of composite floor,and the form and set position of connector affect the bearing capacity and yield performance of composite floor.When the connecting position was set on direction of span and direction of support,the bearing capacity of composite floor mainly depends on connector set on direction of support,and different loading method has obvious effect on deformation resistance ability.When connecting position is set on midspan,the deadweight increment of composite floor had stronger effect on bearing capacity with the increment of span.For the normal service load and construction load,the strength and stiffness of connectors and connecting reinforcement should be separately designed.The bearing capacity and deformation resistance ability of the composite floor decreased substantially with the increment of span.However the relative slip between the upper post pouring mortar of the composite floor and precast slab is quite small,and the embedded thin-walled steel beam can prevent the slip of interfilled concrete.