人工气候环境下粉煤灰混凝土微环境温度响应预计

Micro-environment temperature response prediction for fly ash concrete in artificial climate environment

从混凝土传热过程的基本理论出发,结合人工气候环境下粉煤灰混凝土导热系数的试验结果,研究了粉煤灰混凝土微环境温度响应规律及响应预计模型.结果表明:粉煤灰混凝土导热系数随着粉煤灰掺量的增大而逐渐降低,但随着微环境相对湿度的增大而逐渐增大,且影响规律基本服从线性关系;粉煤灰掺量的提高使混凝土内外环境温度响应速率减慢(微环境相对湿度一定);粉煤灰混凝土内微环境相对湿度(孔隙水饱和度)的增大,使粉煤灰混凝土内外环境温度响应速率加快;混凝土微环境温度与外界环境温度响应实质为传热学上的非稳态传热问题,且理论分析与试验结果吻合较好.

Heat conduction theory was used to predict the temperature response of fly ash con- crete. Measured thermal conductivity values were obtained in artificial climate environment. The thermal conductivity of the concrete drops as the amount of fly ash in the concrete in- creased. Thermal conductivity also increased as the relative humidity of the environment rose. These are linear relationships. Higher fly ash content reduces the sensitivity of the thermal conductivity value to environmental humidity. Response rate to thermal changes is higher at higher relative humidity. The thermal response of the samples is a non-steady state heat conduction problem and our theoretical analysis agreed well with the experimentally observed results.