湿-烘循环作用下PVA纤维增强水泥基复合材料抗氯离子侵蚀性能研究

Research on Chloride Erosion Resistance of Polyvinyl Alcohol Fiber Reinforced Cementitious Composites(PVA-FRCC) under Wet-dry Cycles

采用湿-烘循环的试验方法，以PVA纤维体积掺量和烘干温度为参数，研究了PVA纤维增强水泥基复合材料（PVA-FRCC）的抗氯离子侵蚀性能。结果表明：湿-烘循环作用下，随着PVA纤维体积掺量逐渐增加，PVA—FRCC试件氯离子平均侵蚀深度变化幅度较小，而氯离子最大侵蚀深度逐渐降低。与同等条件下混凝土相比。氯离子最大侵蚀深度约降低20．9％-48．9％，同时，同一侵蚀深度处自由氯离子浓度明显降低。随着烘干温度的升高．PVA—FRCC试件氯离子平均和最大侵蚀深度增长明显；相同侵蚀深度处自由氯离子浓度明显增加。PVA纤维体积掺量和烘干温度对PVA—FRCC抗氯离子侵蚀性能有较明显的影响。

Chloride erosion resistance of polyvinyl alcohol fiber reinforced cementitious composites （PVA-FRCC）is studied by wet-dry cycles and setting PVA volume fraction and dry temperature as evaluation index. The results show that, with the increasing dosage of PVA fiber, the average erosion depth range shows little change under wet-dry cycles, but the maximum erosion depth decreases slowly. Compared with concrete in the same condition, the maximum chloride erosion depth decrease by 20.9% to 48.9%, meanwhile, concentration of free chloride ion in the same depth becomes lower. With the dry temperature increasing, the average erosion depth and maximum erosion depth of PVA-FRCC increase significantly, that is similar with concentration of free chloride ion in the same depth. PVA fiber content and dry temperature have great influence on chloride resisting properties of PVA-FRCC.