Research And Application On Phosphogypsum As Auxiliary Materials And Reinforced Concrete Of Spatial Grid Frame Structure

With the social development,urban land increase tense,and people put forward higher requirement to the living and working conditions,therefore,the new buildings are almost high-rise buildings.The types of high-rise building are frame structure,frame-shear wall structure,tube structure,framework-core tube structure and the giant structure etc.The traditional frame structure has a history for more than 100 years.From the energy point of view,a new structural system is proposed firstly in this paper,namely the phosphogypsum as auxiliary materials and reinforced concrete of spatial grid frame structure,which has better shear stiffness and can overcome the disadvantages of the traditional frame structure,such as big beams and columns,beams supporting walls,and form large column grid,space and free partition.The new structure are made up cast-in-place phosphogypsum filling wall,grid frame wall and phosphorus gypsum mould box hollow ribbed slab floor.Wall and hollow ribbed floor form the grid frame structure.The new structure system is the prototype of the reinforced concrete spatial grid box structure and assembly integral steel spatial box structure used.Phpsphogypsum used in the buildings,usually the masonry block,not only the the speed is slow,and the block of phosphorus gypsum admixture is generally below 50%.This paper proposes for the first time the phosphogypsum by pouring casting method for outer wall,greatly accelerate the construction progress,and the phosphorus gypsum admixture of up to 85%.In view of the phosphorus gypsum fast coagulation time,poor water resistance and other characteristics,through the experimental study to determine the reasonable ratio of phosphogypsum grouting material,the initial setting and final setting time and meet the requirement of construction technology,the compressive strength was slightly higher than common sintered brick,radioactive conforms to construction materials standards;through the cement mortar in phosphogypsum wall scraping special gypsum binders,interface agent and adding polymer mortar anti cracking agent,to solve the phosphogypsum wall softening,waterproof and antipermeability performance.By integrating with the Natural Science Foundation of China "Study on the failure mechanism and load-bearing design of cast phosphogypsum load-bearing walls and cast grid frame structure combinated walls with phosphogypsum and concrete”(NO.51168008),Guizhou Provincial Science and Technology "Study on the low,medium and high-rise residential energy-saving building with phosphogypsum as the main and auxiliary materials"(Z083061),the research is studied by the paper.The main research and investigation are done as follows:(1)By studying the mechanical properties of industrical solid waste phosphogyps-um produced by Weng Fu Group,and identified the reasonable ratio of cast with phosphogypsum wall grout,which meets the construction process,radioactive,wall drying requirements.Combined with the actual construction methods,the pouring phosphogypsum wall-site construction methods of operation and exterior waterproofing practices are given.(2)Describes the composition of the structure:phosphogypsum as the cast infilled walls,the spatial grid frame structure walls and ribbed hollow plate with phosphogypsum mold box.The mechanical properties of comparative analysis between single specimens of the grid frame and conventional frame structure,propose the practial design methods for ribbed hollow plate with phosphogypsum mold box,and compare the results with the finite element method.(3)Experimental research of grid frame structure walls and the conventional frame structure walls at the level of low cyclic loads are done,and study the hysteretic curves,skeleton curves,ductility and energy dissipation,the comparision with the conventional frame structure.(4)Make nonlinear finite element analysis of the test model,using concrete damage plasticity model,the maximum horizontal bearing capacity of the finite element analysis results agree well with test results,but the finite element hysteresis curve fuller than the test results.With the increase of axial compression ratio,the maximum horizontal bearing capacity improves,but the energy dissipation capacity further weakened.(5)Carry out continuous analysis.Continuous analysis calculation method is simple and reliable,and can be directly applied to practical engineering,the results coincide with the finite element results.(6)It is important to select the seismic waves durning elastic dynamic analysis.The results of elastic-plastic static analysis agree with the dynamic elastic-plastic time history analysis.Because elastic-plastic dynamic analysis takes a long time,usually can be carried out elastic-plastic static analysis to find the weak layer in order to take appropriate measures to strength the weak layer.(7)Analyze the factors affecting the mechanical properties of the grid space framestructure,and given a reasonable mesh size.Combined with an example,design respectively by using conventional frame constructure and spatial grid framework,conduct a comprehensive analysis of its cost and overall performance.When using the latter,have a good economic and social benefits,reduce the pollution of the atmospheric environment,and the cast gypsum wall facades to meet energy requirements.