Study On The Failure Mechanism Of Steel Pumice Concrete Composite Two-way Slab

Pumice concrete is a kind of concrete material with good stress performance and light weight.The steel concrete composite floor formed by combining light steel keel as the internal section steel has better stress performance and overall performance.In this paper,pumice concrete and steel keel are used as the main load-bearing components to form a steel pumice concrete composite two-way floor,and its failure mechanism under the action of vertical uniform load is analyzed.In order to study the failure mechanism of steel pumice concrete composite two-way floor slabs,ABAQUS was used to establish a finite element model of steel pumice concrete composite two-way floor slabs.The force mode and deformation characteristics of the composite floor slabs were studied under the action of vertical loads,and the thickness of the floor was considered.The influence of section steel keel spacing,section steel wall thickness and section steel height on the mechanical properties of section steel pumice concrete composite two-way floor.According to the results of finite element analysis and combined with the basic theories of material mechanics and elasticity,the deformation and bearing capacity of steel pumice concrete composite slabs are theoretically analyzed.Combined with concrete specifications,the deformation resistance of the steel pumice concrete composite slabs is given.The calculation formula.The main contents are:1)The steel pumice concrete composite floor slab has an elastic state before cracking and is in an inelastic state after cracking,and then develops to the elastic-plastic state of partial yield of the steel section,and finally reaches the ultimate bearing capacity..2)As the thickness of the floor slab increases,the bearing capacity of the steel pumice concrete composite floor slab increases geometrically.With the increase of section steel keel spacing,the bearing capacity of section steel pumice concrete composite two-way slab gradually decreases,and the deformation capacity also decreases.With the increase of section steel wall thickness,the bearing capacity of section steel pumice concrete composite two-way slab gradually increases,and its deformation capacity also increases.With the increase of the height of the section steel keel,the bearing capacity of the section steel pumice concrete composite two-way slab gradually decreases,and the deformation capacity basically does not change much.3)The increase in floor thickness has the most obvious effect on the vertical bearing capacity of the composite floor.In the case of a certain floor thickness,increasing the section steel spacing will reduce the bearing capacity of the composite floor,and the deformation capacity will also decrease.In the case of a certain floor thickness,increasing the thickness of the profiled steel flange has the most obvious effect on improving the bearing capacity of the composite floor.4)In the calculation of the section steel pumice concrete composite floor,it is assumed that the section steel upper flange and the compression zone concrete resist the pressure generated by the bending moment on the upper flange,and the section steel lower flange resists the tension generated by the bending moment on the lower flange.,Regardless of the section steel web participating in the bending,the section steel web mainly bears the shear force of the member.Combined with the design code of concrete structure,the deflection calculation formula of steel pumice concrete composite floor is deduced,and compared with the finite element calculation results,the results show that the deflection calculation formula given in this paper is reasonable.5)This paper gives the calculation formula for the moment bearing capacity of steel pumice concrete composite floor under uniformly distributed load.The calculation result and the finite element calculation result have relatively small errors,which verifies the rationality of the moment bearing capacity calculation formula in this paper.The calculated value of the theoretical formula obtained in this paper is less than the ultimate bending moment value of the entire composite floor.Therefore,the calculation result of the bending moment bearing capacity calculated in this paper is safe and can be used in the actual engineering design of the steel pumice concrete composite two-way floor.