Study Simultaneous Heat and Moisture Transfer in Concrete Slab under Fire Resistance Test.

找出了影响耐火试验结果的因素。对试验数据进行了收集和分析，发现强度较大的试件具有较高的耐火性，表现出典型的温度蠕变，与识别的因素也有较好的相关性，但较弱的试件耐火性能较差，相关性较差。在ORDR中，为了了解火灾因素的影响，进行了真实尺度试件的阻力试验。主要研究结果如下：在等温时积分下进行加热，较高的溶质温度导致较高的后表面温度，底盖板有利于降低后表面温度，采用柏木板压制热电偶的JIS方法比ISO方法引起较高的温度，低初始温度下的试验比较高温度下的试验更有利，含水率越高，蠕变时间越长，温度也越低，金刚砂、轻质混凝土和普通混凝土试件的后表面温度依次降低。采用扩散模型进行了数值计算，计算结果与实验结果吻合较好，采用对角隐式龙格-库塔法计算稳定，计算速度快。计算表明，在可能的测试条件下，对温度的修正应按以下顺序进行：导热系数、炉温、水分、热电偶设置方法、初始空气温度和冷却过程。

The factors affecting the result of fire resistance test are identified. The experimental data are collected and analyzed, and found the specimen which is strong is highly fire resistant and shows typical temperature creeping and also good correlation to factors identified, but the weaker shows less fire resistance and poor correlation. In ordr to see the effect of factors fire, resistance test for the real scale specimens are carried. Main findings are as follows if the heating are carried under the equal temperature-time integral, the higher sbsolute temperature cause the higher rear surface temperature, the bottom cover plate is vavorable to reduce rear temperature, JIS method which use cedar plate to press thermocouples cause higher temperature than ISO method, the test under lower initial temperature is favorable than under higher temperature, the higher water content brings longer creeping time and also lower temperature, the specimens made of martar, light weight concrete and normal concrete shows lower rear temperature in this order. The numerical calculations by using diffusion model are carried and showed good agreement to the experiments, diagonally implicit Runge-Kutta method is used to get stable and fast computation. The calculation says the correction for the temperature under probable test conditions should be in the following order, thermal conductivity, furnace temperature, water content, method of thermocouple setting, initial air temperature and cooling process.