表面活性温拌剂与沥青、集料的界面润滑行为机制

The interface lubrication behavior of surfactant additives in warm mix asphalt is a key factor to construct pavement layers with warm mix asphalt, which has a direct effect on the application of the surfactant WMA (warm mix asphalt) technology. At present, both at home and abroad, the quantitative characterization of this interface lubrication behavior has not been achieved. There are mainly two challenges in the study of this interface lubrication behavior. One of them is that the asphalt is liquid at high temperatures, whose surface energy parameters are not easy to measure. Another is the lack of the evaluation indicator of this interface lubrication behavior. The surface energy theory and the lubrication theory will be applied to this study. Firstly, the relationship between the differential capillary method and the sessile drop method will be established. The test method for measuring the surface energy parameters of liquid asphalt at high temperatures will be proposed. Secondly, the effects of shear rates on the viscosity of the asphalt mastic with surfactant WMA additives will be analyzed and the lubrication evaluation indicator based on the viscosity of the asphalt mastic with surfactant additives will be proposed. Thirdly, the main interface indicators that affect the lubrication mechanism will be selected and the quantitative relationship model between these interface indicators and the viscosity of the asphalt mastic with surfactant additives will be established to reveal the interface lubrication mechanism of surfactant WMA additives. Finally, the effects of the compatibility of raw materials and the compaction processes on the lubrication of the asphalt mastic with surfactant additives will be quantitatively analyzed. The criteria for surfactant, asphalt and aggregate selection, and the compaction process improvements will be proposed. The results of this study are of great significance for expanding the application scope of the surface energy theory in the research of asphalt pavement materials and the development of warm mix asphalt technologies. In addition, the results will promote the development of the lubrication theory in tribology.

表面活性温拌剂的界面润滑行为是实现温拌施工的核心机制，直接影响表面活性温拌技术的应用水平。目前，国内外尚未实现对这种界面润滑行为机制的量化表征。研究的难点在于高温液态沥青的表面能参数不易测定，且缺少润滑效果的评价指标。本项目应用表面能理论与润滑理论开展研究。首先，建立差分毛细管法与躺滴法的联系，提出高温液态沥青表面能参数的测试方法。其次，分析剪切速率对温拌沥青胶浆粘度的影响，提出基于温拌沥青胶浆粘度的润滑效果评价指标。再次，优选影响润滑机制的主要界面指标，建立这些指标与温拌沥青胶浆粘度的量化关系模型，揭示表面活性温拌剂的界面润滑行为机制。最后，量化分析原材料配伍性、压实工艺对润滑效果的影响，提出表面活性剂与沥青、集料的选择标准，以及施工压实工艺的改善措施。研究成果对拓展表面能理论在沥青铺面材料研究中的应用范围、推进沥青混合料温拌技术的发展具有重要意义，对于润滑理论的发展具有一定推动作用。

表面活性温拌剂的界面润滑行为是实现温拌施工的核心机制，直接影响表面活性温拌技术的应用水平。本项目应用表面能理论与润滑理论开展研究。首先，推导了差分毛细管法公式，探究表面张力测试的原理、方法及影响因素。其次，分析剪切速率对温拌沥青胶浆粘度的影响，提出基于温拌沥青胶浆粘度的润滑效果评价指标。再次，优选影响润滑机制的主要界面指标，建立这些指标与温拌沥青胶浆粘度的量化关系模型，揭示表面活性温拌剂的界面润滑行为机制。最后，量化分析原材料配伍性，提出表面活性剂的选择方法。研究结果表明：（1）接触角及高度修正对内半径标定影响显著，内半径标定对测试结果影响显著，建议选取内半径生产标号0.10、0.20 mm的毛细管进行试验，改进后的差分毛细管法表面张力测试精度提高24.7%-49.2%以上；（2）计算出沥青混合料压实过程中沥青胶浆所受的剪切速率范围（10-40s-1），结合试验室内布氏旋转粘度仪的剪切速率量程（0.279-25s-1），建议以25s-1作为剪切速率代表值，进行表面活性温拌沥青胶浆的润滑能力评价。（3）表面活性温拌沥青表面张力比与温拌沥青胶浆粘度比具有显著相关性，表面活性温拌剂对高温液态沥青表面张力的降低能力越强，其界面润滑效果越好。（4）温拌沥青胶浆的粘度试验可以作为配伍性的检测方法，温拌剂的种类和掺量是影响温拌效果的主要因素。研究成果对拓展表面能理论在沥青铺面材料研究中的应用范围、推进沥青混合料温拌技术的发展具有重要意义。