Fire Resistance Analysis Of Profiled Steel Sheeting-Concrete Composite Slab

Fire will cause serious damage to the building structure,and cause a large number of economic losses and casualties.At present,composite structures have been universally recognized and widely developed in the building system,but under the action of high temperature,there will be deterioration of materials and reduction of bearing capacity.In order to understand the effect of high temperature on composite structure more clearly,it is necessary to study the high temperature of composite structure.the ABAQUS software is used to study and analyze the temperature field,deformation characteristics,fire resistance and change of stress on profiled steel sheetingconcrete composite slab under fire.The main research contents and achievements are as follows:Firstly,the thermal and thermal performance parameters of steel and concrete were determined;the temperature field of composite slabs were interpreted to result from the different concrete moisture content,thickness of composite slabs,thickness of fire retardant coatings and heating curves.The results showed that: the moisture content of concrete had a certain influence on the temperature rise of the back of slab;the greater the thickness of the slab,the lower the temperature at the back of the slab and the more obvious the insulation;fire retardant coating and heating curve had great influence on the temperature field of composite slab.Secondly,based on the analysis of temperature field and thermo-mechanical coupling,fire resistance of one-way composite slabs were analyzed,considering different the rotation and axial restraint,thickness of fire retardant coatings,length-width ratios,heating curves,loads.The results showed that: the fire resistance of one-way composite slabs were poor;the different loads had little effect on the deformation of the slab in the early stage of fire,but in the later stage;The thickness of protective layer of crackresistant steel had little effect on the fire resistance of slabs;fire resistance of slabs increased with the increase of thickness of fire retardant coatings,end constraint of slabs,slab thickness and the decrease of length-width ratios.Through the analysis of the calculated data,the formula with good coincidence considering the influence of multiple factors was given.Thirdly,fire resistance of two-way slab under Steady-state test and Transient-state Test was analyzed and compared in detail.Then,the fire resistance of two-way slabs under different length-width ratios,end constraints,heating curves and loads were discussed.The results showed that: different loading modes had great influence on the fire resistance of two-way slabs,but both loading modes had film effect on the slabs;the longer length-width ratios deviates from 1.0,the smaller the deflection at the center of composite slab,but under the film effect,the stress of the steel mesh was not uniform;the stronger the restraint at the end of slabs,the smaller the deformation of the slabs;the influence of heating curves on deformation of slabs was hydrocarbon heating curve <ISO-834 heating curve < HC heating curve < RABT heating curve in turn;the magnitude of loads was one of the main factors affecting the fire resistance of composite slabs.