盐分侵蚀对沥青和混合料性能影响及作用机理

发布时间：2018-05-09 13:43

本文选题：道路工程 + 盐蚀　；参考：《长安大学学报(自然科学版)》2017年03期

【摘要】：针对沿海地区降雨、海雾、大气中海盐粒子侵蚀路面材料的问题,开展海水中盐分对沥青及混合料性能的影响及作用机理研究。基于沥青主要技术指标和组分试验,分析了海水及其中各类盐分对沥青主要技术指标和组分的影响;设计了室内盐蚀循环加速模拟试验,评价了盐分和高温耦合作用下沥青混合料的高温稳定性、低温性能、水稳定性以及抗疲劳性能,并结合接触角试验和室内试验结果探讨了盐分和高温耦合作用下沥青混合料性能衰变机理。研究结果表明:经过不同盐分侵蚀后,沥青组分中芳香分和饱和分的含量减小,沥青质含量相对增大,在沥青技术指标上反映为软化点增大,针入度减小;各种侵蚀环境中,海水对沥青针入度和软化点的影响最大,其余依次为NaCl溶液、MgCl_2溶液、KCl溶液、NaSO_4溶液、空气和纯水;海水较纯水更容易浸润集料,也更易侵入沥青和集料的界面,从而降低沥青/集料界面黏结强度;同时,可溶性盐结晶过程中会发生体积膨胀,产生结晶压;这些因素的综合作用使得沥青混合料的高温稳定性、低温抗裂性、水稳定性和疲劳特性均发生了不同程度的衰减。
[Abstract]:Aiming at the problems of precipitation, sea fog and sea salt particles eroding pavement materials in coastal areas, the effect of salt in seawater on the performance of asphalt and mixture and its mechanism are studied. Based on the main technical indexes and component tests of asphalt, the effects of seawater and its salts on the main technical indexes and components of asphalt were analyzed, and the accelerated simulation test of indoor salt corrosion cycle was designed. The high temperature stability, low temperature performance, water stability and fatigue resistance of asphalt mixture under the coupling action of salt and high temperature were evaluated. Combined with contact angle test and indoor test results, the decay mechanism of asphalt mixture performance under the coupling of salt and high temperature is discussed. The results show that after different salt erosion, the content of aromatic and saturated components in asphalt components decreases, and the content of asphaltene increases relatively, which is reflected in the increase of softening point and the decrease of penetration in various erosion environments. The effect of seawater on penetration and softening point of asphalt is the greatest, and the rest are NaCl solution, MgCl2 solution, KCl solution and NaSO4 solution, air and pure water, and seawater is more likely to infiltrate aggregate than pure water, and to invade the interface of asphalt and aggregate more easily. Therefore, the interfacial bonding strength of asphalt / aggregate is reduced. At the same time, volume expansion occurs in the crystallization process of soluble salt, resulting in crystallization pressure. The combined effect of these factors makes the asphalt mixture stable at high temperature and crack resistance at low temperature. The water stability and fatigue properties are attenuated to different degrees.
【作者单位】：长安大学特殊地区公路工程教育部重点实验室;广西交通投资集团有限公司;中铁第一勘察设计院集团有限公司;
【基金】：交通运输部建设科技项目(2013 318 221 150) 陕西省青年科技新星资助项目(2015KJXX-23) 陕西省建设科技计划项目(2015-K99) 中央高校基本科研业务费专项资金项目(310821161016)
【分类号】：U414

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