| Phosphogypsum cavity mold Cast-in-place concrete floor is a new type of structure.Prefabricated phosphogypsum cavity mold box as a permanent construction of internal mold filling material,So that the floor is formed inside the cavity structure.This form of structure not only makes full use of industrial waste phosphogypsum,but also the structural form has the characteristics of light weight,high rigidity,convenient construction and lower layer.Applicable to large column network,large span,large bay and other buildings.At present,the research on the utilization of this structure and the utilization of phosphogypsum at home and abroad is limited.In this paper,the preliminary preparation of the gypsum cementitious material and its physical and mechanical properties,the size and application of the gypsum cavity mold box,the test of the floor cavity component and the finite element simulation were studied.And carried out the following research work:(1)Through the provision of Yunnan Province San huan Chemical Group,the phosphogypsum pretreatment phosphorus building hemihydrate gypsum,and phosphorus building half water gypsum as main cementitious materials,with the addition of additives and admixtures,evenly mixed with water,phosphorus building gypsum cementitious materials.(2)By Phosphorus buliding gypsum plaster compressive strength,flexural strength,elastic modulus,Poisson's ratio of the mechanical properties of measurement,obtained optimum mixing ratio parameters.And the compressive strength of the prepared phosphorus buliding gypsum was 14.8MPa,the flexural strength was 5.3MPa,the elastic modulus was 1486N/mm2,and the Poisson's ratio was 0.12.(3)Study on the shape,production characteristics,construction characteristics,performance and application of the gypsum cavity module of phosphorus buliding gypsum,The size of the gypsum cavity module is reasonable,the mechanical performance is better and the hollowness is high.And with the preparation of phosphorus buliding gypsum casting molding.(4)Through the design of the plaster cavity mold box for the design and production of cavity components,and three different structures of the cavity components of the destruction test,It analyzes the bottom center of the plate under concentrated load displacement effects,stress and strain,and the main part of the development of other hollow member in the destruction of the state of cracks.By comparing the 3 kinds of different structure of the cavity member,2-1-2 three rows of semi ellipsoid gypsumembedded filler hollow member failure load is 246kN,and the main parts of the stress and strain distribution range is small,the crack of diagonal form through X type bottom plate with crack damage.Finally,it is concluded that the shape of the cavity and the position of the cavity of the 2-1-2 three row semi ellipsoidal cavity mold cavity are the most favorable to the stress state of the cavity.(5)The nonlinear finite element analysis of the specimens was carried out by using the finite element software Ansys.In this paper,the deformation,stress,strain and crack of 3 different structures are analyzed.By comparison,it is found that when the cavity of the 2-1-2 three row semi ellipsoidal cavity is cracked,the center displacement of the plate bottom is 0.44mm,and the stress and strain of the main part of the bottom of the plate are smaller.At the same time,the results of finite element analysis are compared with the experimental results.The results show that the distribution of center displacement,stress and strain of 2-1-2 three row semi ellipsoidal gypsum hollow box structure is not significant.And the crack development trend is basically the same. |
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