低水灰比混凝土内部相对湿度变化规律研究

Analysis of Relative Humidity Change in Low Water-cement Ratio Concrete

对用普通骨料及经预湿处理的2种不同吸水率陶粒所制配的0.3水灰比混凝土内部相对湿度变化进行了试验研究。在不同湿度养护环境下,测试沿单轴方向传湿的混凝土试件内不同部位处相对湿度变化情况。结果表明:养护总时间一定时,湿养护时间越长,混凝土内部湿度降低越缓慢;采用预湿陶粒所配制的混凝土内部各点的相对湿度均高于普通骨料混凝土,并且陶粒含水率越高,混凝土内部相对湿度越高;在干燥环境中,混凝土内部湿度与环境相对湿度的差值越大,距离干燥面5 cm以内混凝土试件的相对湿度降低速度越快,距干燥面距离超过10 cm时,环境湿度的影响程度很小;陶粒混凝土内部相对湿度降低速度低于同条件的普通混凝土。

Relative humidity movement of different internal location in an ordinary coarse aggregate concrete and two prewet ceramsite concretes with 0.3 water-to-cement ratio were experimentally investigated. The internal RH-change of concretes with one-dimensional moisture transported was measured, in different RH curing environment. The results indicates that： when the cumulative curing time was a definite value, the internal RH decreased more slowly with the time of moist curing deferred. All location values of internal RH of concrete with pre-wet ceramsite were higher than those values of ordinary aggregate concrete, and the internal RH of concrete was higher with the moisture content of ceramsite increased. In the drying environment, with the increased of moisture difference between concrete internal and environment, the RH decrease rate of internal concrete was fast, where the rang from naked surface to the 5cm location deep, when the rang exceed deep 10cm, influence of environment RH on the internal RH was very slight; internal RH of ceramist concrete decreased slowly than ordinary concrete at the same condition.