自然环境中混凝土内微环境温度响应

Response of Micro Environmental Temperature in Concrete under the Natural Environment

研究了有/无遮挡条件对自然环境中一维混凝土内微环境温度响应的影响规律.基于傅立叶传热原理和第三类边界条件,推导出2种工况下的一维混凝土内微环境温度响应模型,并利用现场试验结果论证了所建模型的合理性;此外,还提出了利用实测结果求解混凝土的热扩散系数和表面换热系数等参数的方法.试验结果表明:所构筑的不同工况条件下的混凝土内微环境温度响应模型可表征混凝土内微环境温度响应变化规律,其理论拟合曲线与实测结果基本吻合;有/无遮挡条件对混凝土内微环境温度响应影响较大,主要体现在温度响应波幅、极值和出现时间等方面,这是因为主导混凝土与环境间的换热方式不同;基于理论推导和实测结果所解出的混凝土热扩散系数和表面换热系数等参数的精度较高.

The response law of micro environmental temperature in one dimensional concrete under the natural environment with/without shelter was studied.Based on the Fourier heat conduction equation and third boundary condition,the response mode of micro environmental temperature in one dimensional con-crete under the natural environment was inferred,and the test was carried out to testify the rationality of the mode.In addition,a new method was summarized to solve the parameters,such as thermal diffusion coefficient and surface heat transfer coefficient.The results show that the modes of micro environmental temperature in one dimensional concrete under different conditions were fitted to describe the temperature response law in concrete.The response laws were observably affected by the condition of with/without shelter,and the differences were manifested in the amplitude,extremum and occurrence time,which was caused by the difference of the heat exchange pattern.The parameters,such as the thermal diffusion coef-ficient and surface thermal conductance,which was inferred from the test,are high precision.