人工气候环境下混凝土内相对湿度响应预测  

Prediction of response of relative humidity in concrete under artificial climate environment

作　　者：蒋建华[1] 袁迎曙[2] 王嵩林[1] 孙冬林 

机构地区：[1]河海大学土木与交通学院,江苏南京210098 [2]中国矿业大学力学与建筑工程学院,江苏徐州221116 [3]上海众谊建筑设计有限公司,上海200092

出　　处：《中南大学学报（自然科学版）》2013年第12期5091-5099,共9页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(50878207);河海大学中央高校基本科研业务费专项资金资助项目(2012B02614)

摘　　要：为研究混凝土内相对湿度与环境相对湿度的关系,开展人工气候环境下混凝土内微环境相对湿度正向、反向响应试验。基于混凝土微环境相对湿度响应试验结果以及传质学基本理论,计算各种试验条件下的混凝土湿气扩散系数。研究环境风速对混凝土反向湿气传输的影响,确定了风速对混凝土反向湿气扩散系数的影响模式。最后,基于混凝土相对湿度响应过程中湿气扩散系数演变规律的分析,确立混凝土等效湿气扩散系数计算表达式,进而建立人工气候环境下混凝土内相对湿度响应预测模型。试验结果表明:恒定人工气候环境下,混凝土内相对湿度严重滞后于环境相对湿度。混凝土湿气扩散系数随混凝土内相对湿度而变化,同时还受混凝土水灰比、温度和初始相对湿度差影响。In order to determine the relationship between the relative humidity in concrete and in external environment, the tests of forward response and backward response of relative humidity in concrete＇s micro-environment were carried out under the artificial climate environment. Afterwards, based on the test results of response of relative humidity in concrete＇s micro-environment and the fundamental theory of mass transfer, the diffusion coefficients of moisture in concrete were calculated under various test conditions. The results show that the internal relative humidity in concrete significantly lags behind the relative humidity in the constant artificial climate environment. The effect of wind speed on the backward transmission of moisture in concrete was studied, and the model of backward diffusion coefficient of moisture in concrete was determined considering the influence of wind speed. Finally, based on the analysis about the evolutions of diffusion coefficients of moisture in the response process of relative humidity in concrete, the calculation expressions for the equivalent diffusion coefficient of moisture in concrete were established, and then the prediction model of response of relative humidity in concrete under artificial climate environment was founded. The diffusion coefficients of moisture vary with the internal relative humidity in concrete, but also are affected by the water-cement ratio, temperature of concrete and the initial relative humidity difference.

关 键 词：人工气候 混凝土 相对湿度 扩散系数 预测模型 

分 类 号：TU528[建筑科学—建筑技术科学]