等温条件下混凝土内部湿迁移规律研究

Study on the Law of Wet Migration in Concrete Under Isothermal Conditions

为探究等温条件下混凝土内部相对湿度演化规律,制作了内部预埋温湿度传感器的圆柱形混凝土试件,对试件圆柱面进行绝湿处理,并利用恒温恒湿环境试验箱与自制可程式湿源在试件两端边界施加不同的湿度,使试件两端产生湿度差,从而实现混凝土内部相对湿度沿单一方向迁移。同时采用恒温恒湿环境试验箱对混凝土湿扩散过程中试件的温度进行控制,探究混凝土温度在20、30、40℃时不同相对湿度边界条件下混凝土内部的湿度演化规律。试验结果表明,混凝土温度越大,湿度响应速率越快,但温度对湿扩散最终稳定状态时试件内部的相对湿度分布影响较小;试件两侧湿度差越大,湿度增幅越大,响应速率相较于湿度差小的试件存在一定的滞后性。

To explore the evolution rule of internal relative humidity of concrete under the isothermal condition,the cylindrical concrete specimens with pre-buried the temperature and humidity sensors were made.The cylindrical surface of the specimens was all wet processed.The boundary of different humidity on both ends of the specimen was exerted with the constant temperature and humidity environmental test chamber and homemade programmable wet source to produce humidity difference on both ends of the specimen.Thus,the relative humidity in the concrete can migrate along a single direction.At the same time,a constant temperature and humidity environment test chamber was used to control the temperature of the specimens in the process of wet diffusion of concrete.The evolution law of the humidity inside the concrete under different relative humidity boundary conditions was explored when the concrete temperature was at 20℃,30℃and 40℃.The experimental results show that the higher the temperature of concrete is,the faster the humidity response rate is,but the temperature has little effect on the relative humidity distribution in the specimen at the final steady state of wet diffusion.The larger the humidity difference between the two sides of the specimen,the greater the increase of humidity is.Compared with the specimen with smaller humidity difference,the response rate has a certain lag.