ABSTRACT
To study the variation and distribution characteristics of relative humidity of early-age concrete and establish the relationship between temperature and relative humidity of concrete, an internal humidity monitoring test and adiabatic temperature rise test was carried out for three groups of concrete with different strengths. According to the test results, in the time domain, the concrete humidity field is divided into the vapor saturated stage and the humidity decline period. In the spatial domain, the humidity is distributed in a gradient along the height direction. The initial moisture distribution with an increasing trend from bottom to top makes the crash time of concrete in a sealed state decrease from top to bottom along the depth direction, while external drying will advance the crash time. The self-drying of concrete decreases with the increase of the water-binder ratio. The influence of external drying on the internal relative humidity of concrete decreases with the increase of the distance from the dry surface and does not affect the range beyond 8 cm from the dry surface. When the relative humidity of C30, C50 and C60 concrete is lower than 97%, 93% and 88%, the rate of hydration is close to 0.
