混凝土在单轴压缩腐蚀介质作用下的气渗性

Study of Gas Permeability of Concrete under Uniaxial Compression in Erosion Medium

将受单轴压应力作用的普通混凝土分别置于人工海水和 5%MgCl2 溶液中腐蚀 ,研究混凝土气体渗透系数的变化特点 .结果表明 :当预置应力比小于阈值时 ,该应力比值的大小对混凝土气体渗透系数没有影响 ;在 1年内 ,随腐蚀介质作用时间的延长 ,混凝土气体渗透系数逐渐减小 ;经 5%MgCl2 溶液腐蚀 1年后的试样 ,其气体渗透系数的预置应力比阈值较同条件下人工海水腐蚀的试样至少小 0 .2 .

The characteristics of gas permeability of concrete were studied, the samples of concrete under uniaxial compression were immersed in the artificial seawater and in the 5% MgCl 2 solution separately. The study results show that the stress ratio of beforehand loading can not affect gas permeability of concrete during the stress ratio f y/ f c,28 d ≤0.6; The coefficient of gas permeability gradually decreases with extending the time of immersion corrosion for a year; After one year in 5% MgCl 2 solution the threshold of stress ratio of beforehand loading for gas permeability is 0.2 lower than in the seawater.