温拌再生沥青结合料融合体系的纳观粘附特性及其微观机理研究

回收沥青与新沥青、再生剂和温拌剂构成的融合体系是影响温拌再生沥青混合料水敏感性的关键。然而，多因素耦合条件下融合体系状态的不确定性使得当前的粘附性影响机制研究存在两大瓶颈：纳观粘附性的精准表征、微观机理的同步阐释。为此，本项目拟开展温拌再生沥青融合体系纳观粘附性及其微观机理的系统研究。具体内容包括：构建基于原子力显微镜（AFM）的融合体系纳观粘附性原位表征方法并基于表面能理论进行可靠性验证；采用AFM原位表征技术研究原材料组成对深度融合体系纳观粘附性的作用规律，建立基于纳观粘附指标的温拌再生沥青原材料组成选择模型；研究原材料、拌合与老化条件等耦合因素对融合沥青与“黑石头”界面过渡区纳观粘附性的影响；采用AFM、GPC与FTIR研究融合体系微观结构的形成机制及其对纳观粘附性的影响机理。研究成果将为客观评价温拌再生沥青的粘附性和改善温拌再生沥青混合料的水敏感性奠定理论与技术基础。

Blending system is composed of reclaimed asphalt pavements (RAP) binder, virgin asphalt, rejuvenating agent and warm mixture asphalt (WMA) additives, which has a critical effect on the moisture susceptibility of warm mix asphalt mixtures containing RAP. However, the uncertainty of the blending system state under the multi-factor coupling conditions has led to two major bottlenecks in the current research on the influence mechanism of the adhesion, i.e., the accurate characterization of the nano-scale adhesion and the simultaneous interpretation of the microscopic mechanism. To solve these problems, this research project aims to carry out a systematic study on the nano-scale adhesion and microscopic mechanism of blending system in warm mix asphalt mixtures containing RAP. There are four main themes in the project. Firstly, the in-situ characterization method of nano-scale adhesion of blending system will be constructed using atomic force microscopy (AFM), which would be verified based on the surface free energy theory. Secondly, the selection model of raw material composition of warm mix asphalt containing RAP will be established using nano-scale adhesion index based on research conclusion in effect of raw material composition on the nano-scale adhesion of deep blending system by developed AFM in-situ characterization technique. Thirdly, the influence of the complex factors including raw materials, mixing and aging conditions on the nano-scale adhesion of blending asphalt and RAP aggregate interface transition zone will be analyzed. Fourthly, the formation mechanism of the microstructure of the blending system and its influence mechanism on the nano-scale adhesion were studied using AFM, GPC and FTIR. The research results from this project will provide theoretical and technical evidence to evaluate the adhesion of warm mix asphalt binders containing RAP and improve the moisture susceptibility of warm mix asphalt mixtures containing RAP.