侵蚀对透水纤维沥青混合料水稳定性的影响

沥青路面在冬季容易受到融雪剂的侵蚀，对道路的性能产生影响，不利于行车安全。为此，通过设置盐分浓度、种类以及聚酯纤维掺量三个变量来研究不同环境下透水沥青混合料水稳定性的变化情况。在透水沥青混合料中掺加不同掺量的聚酯纤维（0.3%、0.35%、0.4%、0.45%、0.5%），选用矿料级配PAC-13制作马歇尔试件。并将试件放在不同浓度的NaCl盐溶液（0%、13%、26%）中，以及不同浓度的Na2SO4盐溶液（0%、8%、16%）中，进行侵蚀以及冻融。由试验结果得出：盐分对透水纤维沥青混合料的侵蚀随着两种盐溶液浓度的增加而更加严重；并且，盐溶液浓度越大，冻融劈裂抗拉强度比越小，说明试件的水稳定性越差；相较于NaCl溶液，Na2SO4溶液对试件的侵蚀更明显。聚酯纤维的掺量存在最佳值，当掺入0.4%的聚酯纤维时，透水沥青混合料的冻融劈裂抗拉强度比最大，水稳定性最好，抗盐分侵蚀的能力最强。

Effect of Erosion on Water Stability of Permeable Fiber Asphalt Mixture

Asphalt pavements are easily affected by the erosion of deicing salt in winter, causing the terrible road performance; and the pavements are not conductive to driving safety. Therefore, the changes in water stability of permeable asphalt mixtures under different environments are studied by setting three variables of salt concentration, salt type and polyester fiber content. Different amounts of polyester fibers (0.3%, 0.35%, 0.4%, 0.45%, 0.5%) were mixed into the permeable asphalt mixture, and the Marshall specimens were made with PAC-13 mineral aggregate gradation. The specimens were placed in different concentrations of NaCl salt solutions (0%, 13%, 26%), and different concentrations of Na2SO4 salt solutions (0%, 8%, 16%) for erosion and freeze-thaw test. According to the test results: the erosion of the permeable fiber asphalt mixture by salt solution becomes more serious with the increase of the concentration; meanwhile, the freeze-thaw splitting tensile strength ratio decreases with the increase of the salt solution concentration, and the water stability of specimens are worse; compared with the NaCl solution, the Na2SO4 solution will erode the specimen more obviously. There is an optimal value for the blending amount of polyester fiber. When 0.4% polyester fiber is blended, the freeze-thaw splitting tensile strength ratio of the permeable asphalt mixture is the largest, the water stability is the best, and the salt erosion resistance is the strongest.