沥青材料损伤愈合创新试验方法及沥青老化的损伤愈合行为

Under the traffic loading and natural environmental factors, pavement structures will appear various kinds of distress, and the performance of pavements will gradually deteriorate. Many of macroscopic distresses in asphalt pavements are actually due to the steady accumulations of microscopic damages in structural layer materials. The phenomenon that asphalt mixtures have damage healing properties under certain conditions has been known for many years. Damage healing behavior theories, influence factors, evaluation methods for asphalt mixtures have been broadly researched, but they are at an early stage as a whole. In the project, Through the laboratory test, Innovative experimental methods and indicators for damage healing properties of asphalt binder and asphalt mixture will be established. The evaluation indicators and criterion in term of usage classification of asphalt mixtures will be put forward according to structural damage characteristics in asphalt pavements and their healing requirements to asphalt mixtures. By various comparative experiments about rheological and damage-healing properties of aging asphalt materials at the different degrees, the damage healing behaviors of aging asphalt materials will be investigated. The proposed researches will be helpful to understand the mechanism of fatigue failure in asphalt pavements, reveal the laws of medium and long term performance development for pavement materials and structures, find the effective ways to improve the durability of asphalt pavements, and provide valuable guidance for asphalt material selection, mixture composition design, pavement construction, and maintenance in the asphalt pavement engineering.

在行车荷载和自然环境因素作用下路面结构会出现各类损坏，使用功能逐渐衰变。沥青路面的许多宏观损坏是结构层材料微观损伤不断累积的结果。沥青混合料在一定的条件下具有损伤愈合特性，这一现象已被认识多年。目前人们对沥青混合料损伤愈合的行为理论、影响因素、评价方法等进行了广泛的研究，但研究尚处于初级阶段。本项目拟通过实验室试验研究，建立沥青和沥青混合料损伤愈合性能的创新试验方法和指标；结合沥青路面结构的损伤特性及其对沥青混合料愈合性能的要求，研究和建立沥青混合料损伤愈合性能的分类评价指标；通过不同老化程度沥青材料的流变学和损伤愈合指标的对比试验，研究沥青材料老化的损伤愈合行为。这些研究工作有助于进一步认识沥青路面的疲劳破坏机理，揭示荷载、环境因素作用下路面材料和结构的中长期性能变化规律，探索提高沥青路面耐久性的有效途径，并为沥青路面工程中沥青选材、混合料组成设计、路面施工和养护，提供有价值的技术指导。

在行车荷载和自然环境因素作用下路面结构会出现各类损坏，使用功能逐渐衰变。沥青路面的许多宏观损坏是结构层材料微观损伤不断累积的结果。沥青混合料在一定的条件下具有损伤愈合特性，这一现象已被认识多年。目前人们对沥青混合料损伤愈合的行为理论、影响因素、评价方法等进行了广泛的研究，但研究尚处于初级阶段。本项目通过实验室试验研究，初步建立了沥青和沥青混合料损伤愈合性能的创新试验方法和指标；结合沥青路面结构的损伤特性及其对沥青混合料愈合性能的要求，研发了沥青混合料损伤愈合性能的初步评价指标；通过将二维纳米尺度材料蛭石和零维纳米尺度材料纳米氧化锌复配、有机可逆热致变色材料应用、针对SBS改性沥青的改性剂分离及再生剂研发等技术手段，揭示了沥青/改性沥青耐光热老化的机理、损伤愈合行为及其评价指标；针对冷再生混合料在施工及长期服役过程中温度和荷载的影响，探讨了原始级配的改变和沥青老化对再生沥青混合料力学性能的影响。这些研究工作有助于进一步认识沥青路面的破坏机理，科学地评价沥青和沥青混合料的损伤愈合性能，理解沥青材料老化过程及其损伤愈合行为，揭示荷载、环境因素作用下路面材料和结构的中长期性能变化规律，探索提高沥青路面耐久性的有效途径，并为沥青路面工程中沥青选材、混合料组成设计、路面施工和养护，提供有价值的技术指导。