The Research On High Temperature Deformation And Thermal Stress Simulation Of High Performance Concret

High performance concrete has been used in various civil engineering fields because of its excellent overall performance.However,due to its high compactness,it will burst and fall off because of internal vapor,thermal strain and stress when it under fire condition,and its bearing capacity will decrease,then the building will collapse,human's life will be threatened,therefore,exploring the high temperature effect of high performance concrete,revealing the regulation of macroscopic bearing capacity and internal strain in high temperature,it has great theoretical significance and engineering value.Depending on National Natural Science Foundation(51478290),exploring the mechanical properties of the high performance concrete C60 when it is in high temperature;Discussing the high temperature effects on internal temperature field and thermal strain of concrete slab with the help of high-temperature thermocouple and vibrating wire strain meter,the cracks ? component deformation and thermal stress preliminary simulation of high performance concrete slab was carried out by ABAQUS simulation software,the main contents are as follows:I.Basic macroscopic mechanics on high performance concrete,it included axial compressive strength,elastic modulus,splitting tensile strength after high temperature,all above contain polypropylene fiber(0.2%)concrete and ordinary concrete.The results show that the various properties decrease with the increasing of temperature generally,and the ordinary concrete declines fast than polypropylene fiber concrete,then build a relationship curve about mechanical properties and temperature.II.Thermal strain tests on high performance concrete slab,the author built many concrete slab with polypropylene fiber(0%,0.1%,0.2%,0.3%).With the help of vibrating wire strain gauge,thermocouple and reinforcement mesh,the thermal strain and temperature in different depth of concrete slabs were tested in high temperature resistance furnace,the results show that thermal strain increased with the increasing of temperature generally,polypropylene fiber's thermal strain is lower than ordinary concrete,and thermal strain decrease with the decreasing of polypropylene fiber,thermal strain will be lower near reinforcement mesh.III.Experimental study on high temperature concrete when it under the circumstance of flame and load,the author built many concrete slab with polypropylene fiber(0%,0.1%,0.2%,0.3%)with the help of vibrating wire strain gauge,thermocouple and reinforcement mesh,there are some load on concrete slab,and put it on flame,the results show that thermal strain increased with the increasing of temperature generally,the speed is faster than high temperature resistance furnace.?.High temperature stress preliminary simulation research on high performance concrete slab,the author measured the thermal stress with polypropylene fiber(0.2%)of concrete slab by using ABAQUS software,in order to combine with practical engineering,the author selected a larger concrete slab to simulation research.Simulation and practical results were different reluctantly because ABAQUS didn't consider some factors,such as pore,vapor and homogeneous,so the both results were different obviously,the results show that temperature and thermal strain trends appeared in the direction of thickness,compared with the practical experiment,temperature and thermal strain were decreasing with time are in the same generally.