压力下水泥基材料中水分传输规律的研究

Moisture transport regularity in cement based material under the water pressure

通过试验得到了水分传输过程中质量随加压时间、压力大小、饱和度、水灰比的变化,并分析了压力下非饱和水泥基材料水分传输方程。研究认为,初始饱和度越小,外压力越大,水分传输速率越快;水灰比减小可以减小孔隙率,从而降低传输速率;在非饱和区域,水泥基材料水分传输是受毛细势和外水压力共同控制。加压前期,毛细势为水分传输主要驱动力,随着饱和度逐渐提高,饱和区也逐渐扩大,外水压力逐渐取代毛细势而成为水分传输的主要控制因素。

In this study the change of water quality versus pressure, saturation and the W/C during water transport process was obtained and unsaturated cement based material transfer equation under water pressure also be analyzed.The results show that the smaller the initial saturation, the external pressure, the greater the moisture transmission rate faster.W/C can decrease porosity, thus reduce the transmission rate; In unsaturated zone, water transport on cement base material is controlled by the capillary potential and hydraulic pressure.At the be- ginning,the capillary potential leads to the main driving force for moisture transmission,with the higher water saturation of the wetting front moves, fully saturated zone gradually expanded.Consequently, hydraulic pressure gradually replaced the capillary potential and be- come the main driving force of the moisture transmission.