变温条件下大体积混凝土内部温湿度演化规律与驱动机制  

Evolution Law and Driving Mechanism of Internal Temperature and Humidity of Mass Concrete Under Variable Temperature Conditions

作　　者：卢晓春[1] 双宁 陈博夫 阴国强 刘晓 LU Xiaochun;SHUANG Ning;CHEN Bofu;YIN Guoqiang;LIU Xiao(College of Hydraulic and Environmental Engineering,China Three Gorges University,Yichang 443002,China)

机构地区：[1]三峡大学水利与环境学院,湖北宜昌443002

出　　处：《人民黄河》2023年第3期146-150,共5页Yellow River

基　　金：国家自然科学基金青年项目(52109158)。

摘　　要：针对环境温度变化下的大体积混凝土内部温湿度时空演化问题,浇筑了高1.0 m、直径0.8 m的混凝土试件并预埋了温湿度传感器,在人工气候环境实验室中探究了环境温度从20℃到0℃周期性变化条件下大体积混凝土内部温湿度演化规律。结果表明,变温条件下混凝土内部温湿度演化时空特性具有明显差异,混凝土内部的温度响应随着热传导距离的增加具有明显的滞后性,而受温湿耦合作用影响,混凝土表面湿度对变温环境响应迅速。在环境温度变化而环境湿度不变的条件下,混凝土内部温度的变化主要源于变温环境导致的内外温差和内部温度梯度的作用,而混凝土表面湿度受到了混凝土表面温度梯度比较明显的影响,其平均影响占比达到了86.2%,温度梯度引起的热湿扩散效应远大于自由扩散效应且湿度迁移的速度随局部温度梯度的增大而加快。Aiming at the spatial-temporal evolution of temperature and humidity inside mass concrete under the change of external environment temperature, mass concrete specimen with diameter of 0.8 m and height of 1.0 m was poured, where temperature and humidity sensors were embedded. And the evolution law of temperature and humidity inside mass concrete under variable environmental temperature was explored. The results show that the temporal and spatial characteristics of temperature and humidity evolution inside concrete under variable temperature condition are significantly different. The hysteresis of internal temperature response increases with the increase of heat conduction distance. Due to the coupling effect of temperature and humidity, the surface humidity of concrete responds rapidly to the variable temperature environment. With the varying environment temperature and constant environment humidity, the change of concrete temperature is mainly due to the internal and external temperature difference and the internal temperature gradient caused by the variable temperature environment. The humidity of concrete surface is obviously affected by the temperature gradient of concrete surface, and the average influence ratio is 86.2%. The thermos-moisture diffusion caused by temperature difference is much greater than free diffusion and the velocity of moisture migration increases with the increase of temperature gradient.

关 键 词：变温 大体积混凝土 温湿度 湿迁移 驱动机制 

分 类 号：TV544[水利工程—水利水电工程]