盐冻作用下钢渣矿渣混凝土的渗透性能

PERMEABILITY OF STEEL SLAG AND BLAST FURNACE SLAGE CONCRETE EXPOSED TO SALT FROST

通过测量盐冻作用下钢渣矿渣混凝土的氯离子扩散系数和混凝土断面的气孔形貌,研究钢渣矿渣、水灰比和引气剂对混凝土渗透性能的影响。结果表明:磨细钢渣矿渣的掺入能够减缓硬化混凝土渗透性增大速率,增大混凝土暴露于盐冻环境时的抗渗性。水灰比为0.39的混凝土抗渗性能可以保持较长的冻融循环次数而不明显增大,而水灰比为0.6的混凝土的抗渗性随着冻融循环次数的增大基本呈线性增加。经过200次盐冻作用后,引气混凝土的质量损失明显小于非引气混凝土,但渗透性最终将超过非引气混凝土,混凝土内的气泡多分布在界面过渡区内,随着冻融循环次数的增加,气孔孔径和连通度增加。

The effect of steel slag and blast furnace slag,water to cement ratio and air-entraining agent on concrete permeability was studied by measuring the chloride ion diffusivity coefficient and pore feature of cross section of concrete exposed to salt frost.The results showed that increase rate of permeability of hardened concrete would slow down,and impermeability of concrete would increase with the addition of ground steel slag and blast furnace slag.Although exposed to salt frost for a long time,permeability of concrete with the water to cement ratio of 0.39 increased not obviously.The permeability of concrete with the water to cement ratio of 0.6 showed a linear increase with the increase of freeze-thaw cycles;Permeability of air-entrained concrete would surpass the permeability of non-air entrained concrete ultimately.Most air bubbles in concrete were distributed in interface transition zone and,connectivity and diameter of air bubbles increased with the increasing of freeze-thaw cycles.