基于双向形状记忆效应的沥青路面裂缝修复机理研究

Cracking is one of the main diseases of asphalt pavement with semi-rigid base layers. Sealant debonding and Low service life are major problems of crack sealings at present. Two-way Shape Memory Polymers(SMP) are used as sealant in this project to study its mechanism of active following pavement crack expansion. Firstly, design the multi component of crystalline polymer base on analysis of the working conditions of asphalt pavement cracks. Secondly, found the thermodynamics constitutive model of two-way SMP base on study of molecular crosslinking state of crystalline polymers, internal stress and conformation entropy change during crack sealing. Describe the thermodynamic behavior and entropy elastic effect of molecular chain segments of SMP. Reveal the principle of two-way shape memory effect of crack sealing of Asphalt Pavement. Finally, recommend the idea of reduplication repair of asphalt pavement cracks from regenerative angle. Improving the service life of asphalt pavement crack sealings through activing recovery degree of SMP step by step base on aging condition of sealants. This project provides a new way to repair asphalt pavement cracks.

开裂是我国半刚性基层沥青路面主要的病害形式之一，现有裂缝开槽修补存在修复料与沥青路面粘结易失效及耐久性不足的问题。本项目采用双向多级形状记忆聚合物复合材料进行沥青路面裂缝修补，研究其主动追随路面裂缝伸缩变形机理。本项目首先分析沥青路面裂缝工作条件，提出双向形状记忆多组分结晶聚合物本征结构设计；其次，分析双向形状记忆聚合物多次可逆形变过程中结晶聚合物分子交联状态、内部应力与构象熵的变化规律，建立热力学本构模型，描述形状记忆聚合物的分子链段热力学行为及其熵弹效应，揭示沥青路面裂缝修复的双向形状记忆效应原理；最后，从再生角度提出沥青路面裂缝多次可重复修复理念，对形状记忆聚合物进行多级训练，根据修补料老化程度，分阶段触发形状记忆聚合物变形回复程度，实现可重复裂缝修复，大幅提高沥青路面裂缝修补耐久性。本项目为更好实现沥青路面裂缝修复提供了新思路。

开裂是我国半刚性基层沥青路面主要的病害形式之一，现有裂缝开槽修补存在修复料与沥青路面粘结易失效及耐久性不足的问题。本项目通过研发具备双向形状记忆效果的液晶弹性体材料实现对沥青路面裂缝的智能修补。首先通过数值模拟分析和试验评价，明确了裂缝修补材料的应力分布特征，提出了形状记忆裂缝修补料的性能指标要求。基于性能需求，研发了具备双向形状记忆效应的液晶弹性体裂缝修补料，通过优化制备工艺和形状记忆训练方法，使裂缝修补料满足所提出的性能指标要求。进而研究了液晶弹性体的双向形状记忆效应，揭示其双向形状记忆效应原理。最后，通过液态金属改性形状记忆液晶弹性体，提高了其韧性和耐久性，并明确了其改性作用机理，进一步提升所研发液晶弹性体作为裂缝修补料的适用性。本项目在沥青路面裂缝智能修补领域迈出了重要的一步，拓宽了新思路，提供了新方法。