The Experimental Studies And Analysis On Temperature Field Of Concrete Members

Concrete structure is the most widely used type of structure. It would have different levels of damage and destruction after fire although material of concrete has obvious thermal inertia. To analyze the temperature distribution of concrete member is an important basic research of fire damage assessment and performance of concrete structure analysis in high temperature conditions, and the premise of conduct fire resistance design, fire endurance analyze and the residual strength calculation after fire.The main research in this paper is as following:(1) On the basis of designing an integration model by heating inside and concrete member outside, the automatic fire simulation test furnace is developed independently. It heats by making use of resistance with concrete members around the heating device. Moreover, concrete members are also the furnace wall and insulation materials. This method is very helpful in saving energy and space. The whole tests in this thesis are conducted on the basis of simulate ISO834 standard fire curve. Experimental results show that HZCS-01IPC automatic fire simulation test furnace is reliable and convenient.(2) According to the size of the furnace, wallboard with single surface subject to fire and beam with three surfaces subject to fire were designed respectively. Experimental studies were conducted to determine the temperature distribution in them. With the methods of fluid inclusions bursting temperature measurement and thermocouples, the experimental program was summarized and the general rules of the two structural elements were presented in this paper. The material of concrete has obvious thermal inertia; it would appear significant variation of temperature gradient at elevated temperature, and form the dynamic, uneven temperature field in the structural members. Certain measure points have'Stagnant time'at early time of the test for the reason of moisture to evaporate. Time and the highest temperature under fire affect temperature field, it is also showed the influence of the heating rate in the test. The method of combining fluid inclusions bursting temperature measurement with thermocouples submitted in this paper was feasible.(3) Taking the surface time-temperature data from experimental result as boundary conditions, and by combining heat transfer theory with computer numerical value simulation, the transient thermal analysis is conducted to the wallboard and beam section temperature field by the finite element analysis program ANSYS. Compare the calculation of ANSYS with the experimental result and analyze the reason for differences between them. Overall, temperature distribution of concrete members'section by the two methods is verified to have consistent general rules.