含盐高湿环境沥青混合料力学特性的劣化

Deterioration of Mechanical Properties of Asphalt Mixture in Salty and Humid Environment

在纯水、5%和10%Na Cl溶液中,采用持续浸泡、干湿循环和冻融循环3种不同方式加速模拟含盐高湿环境对沥青混合料的腐蚀,然后进行劈裂试验,以劈裂强度和氯盐腐蚀因子评价含盐高湿环境作用下沥青混合料性能的劣化情况,并研究了抗剥落剂、纤维、消石灰等对混合料力学性能的改善情况.结果表明:3种不同方式处理后,随着作用次数的增加沥青混合料的空隙率逐渐增大,劈裂强度逐渐减小;在氯盐溶液中干湿循环12次和冻融循环9次后,沥青混合料空隙率和劈裂强度的变化幅度较小;干湿循环方式最能体现氯盐溶液对沥青混合料性能劣化作用,建议在10%Na Cl溶液中干湿循环12次来模拟含盐高湿环境的腐蚀作用;玄武岩纤维改善含盐高湿环境下沥青混合料力学性能的效果最好.

In pure water as well as 5%and 10%NaCl solutions, three ways of continuous immersion, dry-wet cy-cles and freeze-thaw cycles were adopted to speed up the corrosion of the asphalt mixture in salty and humid envi-ronment.Then, the split test was carried out, and the deterioration of the asphalt mixture performance was evalua-ted by using the splitting strength and the chloride corrosion factor.Moreover, the effects of anti-stripping agent, fi-ber and hydrated lime in improving the mechanical properties of the asphalt mixture were also investigated.The re-sults show that （1） for the asphalt mixture treated in three different ways, with the increase of the action times, the void ratio increases while the splitting strength decreases; （2） after the asphalt mixture experiences twelve dry-wet cycles or nine freeze-thaw cycles in the chloride solution, the ranges of the void ratio and splitting strength changes both become narrow;（3） the way of dry-wet cycles displays the best performance in embodying the negative effect of the salty and humid environment on the asphalt mixture performance, and it is thus suggested that twelve dry-wet cycles in 10%NaCl solution should be used to simulate the corrosive effect of the salty and humid environment;and （4） the Basalt fiber achieves the best effect in improving the mechanical properties of the asphalt mixture in the salty and humid environment.