冻融损伤混凝土的渗透性能研究

INFLUENCE OF FROST DAMAGE ON CHLORIDE PENETRATION INTO CONCRETE

通过先冻融后氯盐侵蚀试验,以水灰比为0.6的普通混凝土、引气混凝土和外涂硅烷防水混凝土为研究对象,讨论了冻融损伤程度对混凝土中氯盐侵蚀性的影响规律。试验结果表明,相同条件下,由于外加剂的影响,引气混凝土和外涂硅烷防水混凝土均表现出较好的抗氯盐侵蚀性;当加速冻融循环超过50次后,混凝土中氯离子扩散系数变化的幅值增大。

Three kinds of concrete,normal concrete,air retaining concrete and waterproof concrete,with water cement ratio of 0.6,has been prepared to investigate the effect of freeze —thaw cycles on permeability.The results indicate,in same conditions,the latter two concrete have a good performance to resist the chloride ion penetration after freeze-thaw cycles and the diffusion coefficient of chloride is much less.Furthermore,the bigger change of diffusion coefficient in concrete appears after 50 times of freeze-thaw cycles,which means the freeze-thaw cycles accelerated the degradation of pore structure.