层状硅酸盐与无机纳米粒子复配改性沥青的防老化及机理研究

Asphalt pavement has become the prior choice for high grade highways due to its excellent pavement performance. However, the service life of asphalt pavement is shortened because of the thermo-oxidative and ultraviolet aging of asphalt under the influence of heat, oxygen and ultraviolet light. Therefore, it is of great importance for improving the aging resistance of asphalt to prolong the service life of asphalt pavement and save the precious petroleum resources. Based on the previous research results and the current research status on aging resistance of asphalt at homeland and abroad, this project will modify asphalt by layered silicates and inorganic nanoparticles as compound modifiers to improve the thermo-oxidative and ultraviolet aging resistance of asphalt at the same time. It will avoid the current disadvantages of improving the aging resistance of asphalt that can not improve the thermo-oxidative and ultraviolet aging resistance of asphalt at the same time. The effect of organic modification of layered silicates and surface modification of inorganic nanoparticles on microstructures and aging resistance of asphalt modified by layered silicates and inorganic nanoparticles will be revealed. The objective of this project is to realize the dispersion of nanomaterials with nanometer scale in asphalt and prepare the excellent durable asphalt materials. The changes of properties, microstructures and chemical compositions of modified asphalt before and after thermo-oxidative and ultraviolet aging will be investigated. The aging resistance mechanism of modified asphalt will also be revealed. This project will provide theoretical guidance for preparation of excellent durable asphalt modified by layered silicates and inorganic nanoparticles.

沥青路面具有优良的路用性能，已成为高等级公路的首选路面类型。但沥青在自然气候条件热、氧、光等的作用下产生的热氧和紫外老化严重缩短了沥青路面的服役寿命，提高沥青的耐老化性对于延长沥青路面的使用寿命和节约宝贵的石油资源具有重要意义。基于国内外的研究现状和申请者的前期研究成果，本申请项目将层状硅酸盐和无机纳米粒子进行复配，综合改善沥青的热氧和紫外老化性能，克服目前仅针对沥青的热老化和光老化问题而寻求单独解决对策的弊端。弄清层状硅酸盐的有机插层改性以及无机纳米粒子的表面修饰对层状硅酸盐与无机纳米粒子复配改性沥青结构和耐老化性能的影响，实现无机纳米材料在沥青中的纳米尺度分散，制备具有优良耐候性的改性沥青，探明层状硅酸盐与无机纳米粒子复配改性沥青在热氧和紫外老化过程中性能、结构与组成的变化特征，揭示复配改性沥青的耐老化机理，为采用层状硅酸盐和无机纳米粒子制备具有优良耐老化性的道路沥青材料提供理论指导。

沥青材料在路面建设和服役过程中受到热、水、氧及光等环境因素的作用会发生老化现象，这将严重影响到沥青路面的使用品质和服役寿命。因此寻求合适的耐老化改性剂以同时改善沥青耐热氧和耐光氧老化性能具有重要意义。本项目将层状硅酸盐和无机纳米粒子进行复配，综合改善沥青的热氧和紫外老化性能。探讨了层状硅酸盐的有机插层改性以及无机纳米粒子的表面修饰对层状硅酸盐与无机纳米粒子复配改性沥青结构和耐老化性能的影响，实现了无机纳米材料在沥青中的纳米尺度分散，制备出了具有优良耐候性的改性沥青，揭示了复配改性沥青的耐老化机理。结果表明：（1）通过插层改性和表面修饰可以显著提高无机纳米材料与沥青的相容性，不同层状硅酸盐与沥青均形成了剥离型的纳米复合结构。（2）不同复配改性剂的加入均降低了沥青TFOT老化后的软化点增量、粘度老化指数以及复数模量老化指数，而增加了其残留针入度、延度保留率以及相位角老化指数，这表明复配改性剂都改善了沥青的短期耐热氧老化性能。但是，不同复配改性剂的作用表现出较大的差异性。综合考虑物理和流变性能的实验结果，可以看出纳米ZnO与有机蛭石复配对沥青的耐老化性能改善效果最明显，即为最优复配改性剂组合。（3）复配改性剂按最优组合方式加入后，不同种类基质沥青的高温稳定性和抗车辙能力均得到提高，但其塑性变形能力有一定程度的降低。复配改性剂均能改善沥青TFOT、PAV、UV及自然光老化后的物理和流变性能，并改善了重交90#沥青PAV老化后的低温流变性能，而对阿尔法70#和重交110#沥青的影响很小。（4）与相应空白样相比，复配改性剂的加入显著抑制了沥青在TFOT、UV以及PAV老化过程中羰基的生成以及芳香分向胶质和沥青质的转化，从而使得复配改性沥青表现出较好的耐热氧和耐紫外老化性能。（5）根据项目研究成果，已在国内外重要刊物和国际会议上发表论文15 篇，其中SCI收录12篇，EI 收录1篇，培养硕士研究生2 名，获得授权发明专利2件。