基于毛细流动扩散理论的沥青混合料自愈合行为研究

Fatigue cracking and a series of diseases caused by fatigue cracking have seriously affected the service quality and service life of asphalt pavement. Asphalt mixtures have the capability to heal cracks, which provide a new research ideas and methods for the control of asphalt pavement fatigue cracking. Taking the inverse processing of cracking as the breakthrough point, this project will focus on the mechanism, expression and enhancement of self-healing. Self-healing behavior of asphalt mixtures was attributed to asphalt capillary flow and diffusion in the micro cracks. The self-healing mechanism and behavior equation would be established based on asphalt capillary flow and diffusion theory. The existing evaluation index system is dependent on testing methods and healing temperature. This project would consider real-healing as an inherent property of asphalt mixtures. Based on the Arrhenius equation, the self-healing activation energy would be developed to evaluate and predict the self-healing ability of asphalt mixtures. On the basis of analysis of different influential factors, a mix design method would be put forward to enhance the seaf-healing from the angle of the reasonable materials selection and optimum volumetric parameter. This study will deeply analyze the self -healing mechanism, accurately evaluate self -healing ability, as well as effectively strengthen self -healing capability. Research results will provide a new research method and theory foundation for controlling fatigue cracking of asphalt mixture and extending fatigue life of asphalt pavement.

疲劳开裂及其引发的多种病害严重影响沥青路面服务质量和使用寿命。沥青混合料产生裂缝后具有自愈合行为，这为控制沥青路面疲劳开裂提供了新的研究思路和技术措施。本项目以裂缝产生的逆过程-裂缝自愈合行为作为研究对象，围绕沥青混合料自愈合行为机理、评价方法和增强技术展开研究：将自愈合行为归结为沥青在毛细驱动下流动扩散使裂缝愈合，建立基于毛细扩散理论的沥青混合料自愈合机理与行为方程；在该理论基础上，将沥青完成在裂缝中流动扩散需要的最小能量定义为自愈合活化能，形成基于自愈合活化能的沥青混合料自愈合能力评价方法；以沥青性质、沥青膜厚度、胶浆组成等为重点，系统分析自愈合能力影响因素，从合理选择原材料与优化体积参数角度提出考虑增强自愈合能力的沥青混合料组成设计方法。研究成果旨在实现对沥青混合料自愈合行为的深刻认知、准确评价和有效增强，为增强沥青混合料抗疲劳性能、延长沥青路面使用寿命提供了新的研究方法和理论依据。

疲劳开裂及其引发的多种病害严重影响沥青路面服务质量和使用寿命。沥青混合料产生裂缝后具有自愈合行为，这为控制沥青路面疲劳开裂提供了新的研究思路和技术措施。本项目以裂缝产生的逆过程-裂缝自愈合行为作为研究对象，围绕沥青混合料自愈合行为机理、评价方法和增强技术展开研究：将自愈合行为归结为沥青在毛细驱动下流动扩散使裂缝愈合，建立了基于毛细流动扩散理论的沥青混合料自愈合机理与行为方程；基于多尺度研究，宏观尺度上提出基于自愈合活化能的沥青材料自愈合能力评价方法，细观尺度上引入荧光显微及CT扫描技术对沥青及混合料的愈合过程进行了观测，微观尺度上利用分子动力学模拟技术模拟了沥青自愈合过程的分子运动规律；进一步调查了沥青性质、胶浆类型、分子组成及结构、间歇时间、温度等因素对自愈合能力的影响，最终确定并开发了自愈合微胶囊技术及主动加热技术，实现了对沥青混合料自愈合能力的显著增强。研究成果实现了对沥青混合料自愈合行为的深刻认知、准确评价和有效增强，为增强沥青混合料抗疲劳性能、延长沥青路面使用寿命提供了新的研究方法和理论依据。