除冰盐对沥青路面路用性能长期影响研究

发布时间：2018-08-25 11:42

【摘要】：沥青路面具有表面平整、无接缝、行车舒适、耐磨、震动小、噪声低、施工工期短、养护维修简便等优点，作为高等级路面而被广泛使用。在我国季冻地区，冬季下雪导致路面结冰车辆打滑，为减少由此带来的交通事故，及时撒布除冰盐快速除冰化雪是当今最常用的手段。长期使用除冰盐除冰化雪，人们逐渐发现，建成不久的沥青路面就较早地出现了开裂、坑槽、松散等一些路面病害。因此，研究除冰盐对沥青路面路用性能的长期影响，，以室内试验为基础，分析除冰盐破坏机理并提出相应的养护建议，对季冻区沥青路面的使用具有重要意义。首先，通过配合比设计确定了两种使用较多的路面结构形式：SMA-13沥青混合料和AC-13沥青混合料。选用了两种氯盐类除冰盐进行对比研究，氯化钠除冰盐和复合型除冰盐。创新设计一套冻融循环方式，即采用保鲜盒存放除冰盐溶液和沥青混合料试件，每冻融循环一次往溶液中撒一次除冰盐，致使除冰盐溶液浓度随冻融循环次数的增加而变大，据此对沥青混合料试件进行冻融循环。其次，通过冻融劈裂试验、飞散试验、疲劳试验，分别测定沥青混合料试件在除冰盐溶液冻融循环作用后的水稳定性、低温抗裂性、疲劳性能的衰变情况。对比分析SMA-13沥青混合料和AC-13沥青混合料性能试验结果，对比分析氯化钠除冰盐和复合型除冰盐对沥青混合料路用性能的影响情况。同时，从物理和化学两个方面分析除冰盐对沥青混合料的破坏机理。最后，针对除冰盐对沥青混合料的破坏形式和结果，提出季冻地区道路的养护措施、路面结构类型选择和除冰盐类型选择的建议。试验研究及分析结果认为，经过除冰盐溶液冻融循环后，沥青混合料的水稳定性、低温抗裂性、疲劳性能都有所下降，且性能指标随冻融循环次数即使用年限的增加而降低，降低速度明显。氯化钠除冰盐对沥青混合料造成的破坏程度要比复合型除冰盐更严重，建议在选择除冰盐时应优先选择复合型除冰盐。SMA-13沥青混合料抵抗除冰盐破坏的能力要高于AC-13沥青混合料，建议在有条件的情况下选择SMA-13沥青混合料结构类型。除冰盐对沥青混合料的破坏有物理破坏和化学破坏。物理破坏机理主要是除冰盐溶液结冰膨胀压和晶体结晶膨胀压的作用；化学破坏机理为除冰盐溶液中的离子与沥青争夺对集料表面的吸附作用，导致沥青与集料的剥离。本项目得到了交通运输部西部交通建设科技项目“季冻区公路应对极端气候的快速维护与安全保障技术研究”的资助。
[Abstract]:Asphalt pavement has the advantages of flat surface, no joint, comfortable driving, wear resistance, small vibration, low noise, short construction period, easy maintenance and so on. It is widely used as a high grade pavement. In order to reduce the traffic accidents caused by snow in winter in the seasonal frozen areas of China, it is the most commonly used method to quickly deicing snow by spreading desiccating salt in time. Using deicing salt for a long time, people gradually found that some pavement diseases such as cracking, pothole, loose and so on appeared in the soon after completion of asphalt pavement. Therefore, it is of great significance to study the long-term influence of deicing salt on the pavement performance of asphalt pavement, analyze the mechanism of deicing salt destruction and put forward corresponding maintenance suggestions on the basis of laboratory tests, which is of great significance to the use of asphalt pavement in seasonal frozen area. Firstly, two kinds of pavement structure forms: SMA-13 asphalt mixture and AC-13 asphalt mixture are determined by mix ratio design. Two chloride-deicing salts, sodium chloride deicing salt and compound deicing salt, were selected for comparative study. Innovative design of a freeze-thaw cycle method, that is, the storage of deicing salt solution and bituminous mixture test pieces in a fresh storage box, each freeze-thaw cycle once into the solution of deicing salt, resulting in the concentration of deicing salt solution increased with the number of freeze-thaw cycles. According to this, the asphalt mixture specimen is frozen and thawed. Secondly, through freeze-thaw splitting test, flying test and fatigue test, the water stability, low temperature crack resistance and fatigue performance of asphalt mixture specimens after freeze-thaw cycle in deicing salt solution were measured. The performance test results of SMA-13 asphalt mixture and AC-13 asphalt mixture are compared and the influence of sodium chloride deicing salt and compound deicing salt on the pavement performance of asphalt mixture is analyzed. At the same time, the destruction mechanism of asphalt mixture caused by deicing salt is analyzed from physical and chemical aspects. Finally, aiming at the damage form and result of deicing salt to asphalt mixture, the paper puts forward some suggestions on maintenance measures, pavement structure type selection and deicing salt type selection of road in seasonal freezing area. The test and analysis results show that after freeze-thaw cycle of deicing salt solution, the water stability, low temperature crack resistance and fatigue performance of asphalt mixture are all decreased, and the performance index decreases with the increase of freeze-thaw cycle number and service life. The deceleration speed is obvious. The degree of damage caused by sodium chloride deicing salt is more serious than that of compound deicing salt. It is suggested that the composite desiccating salt SMA-13 asphalt mixture should be preferred to resist deicing salt damage, which is higher than that of AC-13 asphalt mixture. It is suggested that the structure type of SMA-13 asphalt mixture should be selected under the condition of condition. Deicing salt has physical and chemical damage to asphalt mixture. The mechanism of physical destruction is mainly the action of ice swelling pressure of deicing salt solution and crystal expansion pressure, and the chemical destruction mechanism is the adsorption of ions and bitumen on aggregate surface in deicing salt solution, which results in the peeling of asphalt and aggregate. The project was funded by the Ministry of Transportation's Western Traffic Construction Science and Technology Project, "Research on the Rapid maintenance and Safety guarantee of Highway in seasonal Frozen region to deal with extreme Climate".
【学位授予单位】：重庆交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U416.217;U414

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