酸雨对沥青路面抗磨光性的影响机理及试验评价方法研究

Acid rain is becoming more and more common in China, which make it increasingly important to study the anti-polishing performance of aggregates under acid conditions. However, there are very limited research on whether the ranking of various aggregates' polishing values obtained in neutral environment can be applied to the acidic environment. The analysis from the angle of chemical reactions indicates that both acidic and alkaline rocks will be subjected to acid rain corrosion, and that the aggregate angularity sites have the properties of stress concentration and large specific surface area, which will aggravate the softening action of corrosion. In this study, we will observe the effects of acid rain on aggregate and asphalt corrosion in the test by using the microscopic detection technology of scanning electron microscope with energy spectrum analysis system, compare the different methods and evaluate their reliability for using the flat grinder,developed by our research group, and separated accelerated polishing machine test through standard aggregate contrast polishing test,study the effect of pH value, acid rain, acid soaking cycle on the anti polishing property of aggregate, aggregate mixture, and the corresponding asphalt mixture through the flat grinder test, and investigate the anti polishing performance of the aggregate and asphalt mixture under the condition of heavy load and high speed by changing the velocity and pressure of the polishing machine.Road surface texture and tread pattern of geometric morphology were calculated by digital gray level images fractal dimension， and then discreted in space and devided into many equal rectangular element whose height are said by RMS height of sampling points existing in the equal rectangular element. So the coupling of tyre tread pattern and road surface texture was realized.The research results will provide a theoretical basis for the selection of anti-slide aggregates and test evaluation method under acid environment.

酸雨越来越严重，使得研究酸性环境下集料的抗磨光性能越来越重要；在中性环境下得到的各种集料的磨光值排序，能否适用于酸性环境，这方面的研究报道还很少。 从化学反应角度分析表明，无论是酸性或是碱性的岩石，都会遭到酸雨的腐蚀；集料的棱角部位应力集中和比表面积大，会加剧这种腐蚀软化作用。试验上，通过带有能谱分析系统的扫描电镜等微观检测技术，观测酸雨对集料和沥青的腐蚀；通过标准集料的对比磨光试验，对课题组研发的平板磨光机与分离式加速磨光机进行测试比较，分析不同试验评价方法的可靠性；通过平板磨光机试验，研究酸雨PH值、泡酸周期等对集料、集料掺配，及其对应的沥青混合料抗磨光性的影响规律；通过路面纹理与轮胎花纹的耦合数值计算求解胎路接触问题，建立包含摩擦系数随速度和轴压变化关系的轮胎/道路耦合摩擦系数模型,并与试验结果进行对比。研究成果将为酸雨环境下抗滑集料的选择及试验评价方法提供理论依据。

酸雨越来越严重，使得研究酸性环境下集料的抗磨光性能越来越重要；在中性环境下得 到的各种集料的磨光值排序，能否适用于酸性环境，这方面的研究报道还很少。. 采用电镜分析方法鉴定出石料的成份,在集料岩石的成分鉴定的基础上、通过酸不溶性残渣试验（ASTM D3042-2009）以及EDS分析（能谱仪(EDS,Energy Dispersive Spectrometer)），验证了即使是酸性集料，也含有碱性成分，都容易遭到酸雨的腐蚀。. 通过标准集料的对比磨光试验，对课题组研发的平板磨光机与传统加速磨光机测试数据（标准差和极差）进行比较，研究两种磨光机的测试数据的对应关系，开发了新的平板磨光机，测试结果表明提高了平板磨光机的抗磨光试验可靠性。.相对于集料磨光，沥青混合料的磨光试验更接近于真实路面的磨光情况；室内通过沥青混合料的平板磨光试验证明了酸雨对混合料磨光具有明显的影响；我国的雨季大部分时间在夏季，夏季路表温度往往会达到60℃以上，形成强烈的路面蒸发。随着水的蒸发，H+浓度会逐渐增大，从而提高其反应速率，酸雨腐蚀路面的化学反应将进一步加剧。. 模拟了混合料在低速荷载下表面纹理的磨光过程，分析了磨光区域表面纹理的多重分形谱参数变化情况，量化了表面纹理磨光前后的整体与局部特征变化。结果表明，沥青路面表面三维形貌具有多重分形特性。. 分析了沥青路面表面纹理的分段变维分形特性；通过将Persson理论和分段变维分形表面功率谱近似计算理论相结合，建立并验证了基于沥青路面表面分段变维分形的胎/路摩擦理论模型。分形特征参数为描述路面表面纹理的磨光行为提供了新思路。. 研究成果将为酸雨环境下抗滑集料的选择及试验评价方法提供理论依据。