水泥混凝土塑性阶段表面蒸发速率研究

Study on Evaporation Rate of Concrete Surface during Plastic Stage

试验研究了高温低湿环境下新浇筑水泥混凝土在塑性阶段的表面蒸发速率;在自由水蒸发速率模型基础上,通过对混凝土表面蒸发速率相对于自由水蒸发速率随时间变化的数值分析,得到混凝土表面蒸发速率公式.该公式可以较为准确地对一定环境条件下的混凝土表面蒸发速率进行模拟.结果表明:混凝土表面被泌水覆盖时,混凝土表面蒸发速率等于自由水蒸发速率;泌水被逐渐蒸发的过程中,混凝土表面蒸发速率与自由水蒸发速率之比值随时间的增加以一定规律减小.

Evaporation rate from the surface of freshly cast concrete in plastic stage under high temperature and low humidity environment was studied with research variables including wind speed and water-cement ratio.The evaporation rate at concrete surface was determined based on the evaporation rate of the free water,which is capable of simulating the evaporation rate of the concrete under certain environmental conditions.The results show that the evaporation rate of concrete is equal to that of free water when the concrete surface is covered with bleeding water.During the process of evaporation,bleeding water gradually reduces and disappears.