PVA纤维混凝土经冻融后抗氯离子侵蚀性能研究

Study on Corrosion Resistance of PVA Fiber Reinforced Concrete to Chloride Ion after Freeze-thaw Cycles

为探索聚乙烯醇(PVA)纤维混凝土在冻融环境下冻融循环次数对氯离子渗透速率及最佳纤维掺量的影响,通过对冻融循环次数为0～100次以及纤维体积掺量为0～0.2%的PVA纤维混凝土试件进行氯离子侵蚀试验,拟合出冻融次数与氯离子扩散系数之间的关系式。试验结果表明:PVA纤维掺量相同的试件,施加冻融循环次数越多,在相同渗透深度处自由氯离子含量会越高。在冻融循环次数相同时,混凝土试件中自由氯离子含量会因掺入了一定掺量的PVA纤维而减少,且PVA体积纤维掺量为0.1%的试件中,相同渗透深度处自由氯离子含量低于其它掺量的试件。

In order to explore the effect of freeze-thaw cycles on the chloride ion penetration rate and the optimal fiber content of polyvinyl alcohol （PVA） fiber reinforced concrete under freezing and thawing envi- ronments, the chloride ion erosion test was carried out on PVA fiber concrete specimens with 0-100 times freeze-thaw cycles and 0-0.2 % fiber volume, and the relation between the number of freeze-thaw times and chloride ion diffusion coefficient has been fitted. The results show that the higher the number of freezing and thawing cycles, the higher the content of free chlorine ions at the same penetration depth, with the same content of PVA fiber. Besides, the content of frec chlorine ions in concrete specimens will be reduced by adding a certain amount of PVA fiber, the content of free chlorine ion in the same penetration depth is lower than that of other mixed samples in the volume of PVA volume fiber 0.1% When freeze-thaw cycles are the same.