Research On Load-bearing Mechanism Of Bolted Assembled Composite Floor Slabs

The bolted assembly type combined floor slab is a new type of combined floor slab composed of ALC(Autoclaved lightweight aerated concrete)unit board and thin-walled steel beams,connected by bolts,connectors,then pouring cement mortar post-cast layer.At present,the influence mechanism of this new type combined floor slab bearing mechanism and structural parameters on mechanical properties is not clear,we need to carry out systematic research in order to be widely used in engineering.The paper mainly adopts experimental research methods,combined with finite element simulation,to study the mechanical performance and load-bearing mechanism of the composite floor.In this paper,eight bolt-connected prefabricated composite floor slab specimens are designed,and static load test research is carried out.Based on the test results,the location of different unit plate openings,the number of shear connectors,the number of bolts,the width of the steel beam flange,the loading method,the steel wire mesh,the thickness and material of the post-cast layer’s influence on the deformation and bearing capacity performance of the bolted assembled composite floor is analyzed.Based on experimental research,the ANSYS finite element analysis software was used to numerically simulate the composite floor specimen.The influence of ALC unit slab and steel beam height,auxiliary beam crimping parameters and test piece span on the bearing capacity of the composite floor is analyzed.Based on the test results and numerical simulation analysis,the mechanism of the influence of various parameters on the deformation and bearing capacity of the composite floor is further discussed.Based on the existing research,a simplified calculation method for the displacement of the combined floor slab and the ultimate bending capacity of the normal section is established,which is in good agreement with the experimental values after inspection.According to the analysis:(1)The bolted assembly type combined floor slab has high ultimate bearing capacity and bending stiffness;(2)Increasing the distance from the opening of the unit plate to the edge,increasing the number of connectors,increasing the number of bolts,increasing steel mesh,can increase the bending rigidity and ultimate load of the combined floor slab specimens to varying degrees;(3)The use of ceramsite concrete and steel wire mesh in the post-casting layer can reduce the self-weight and at the same time meet the bearing capacity requirements.Increasing the thickness of post-casting layer can continue to improve its deformation performance under stress.(4)The height of the main beam and the length of the unit plate have a greater influence on the overall rigidity of the composite plate.,the height of the ALC plate and the secondary beam and the height of the auxiliary beam have little effect.