Mechanistic Studies of Asphalt Aging Aimed at the Discovery of Anti-aging Additives

今天为市、省和国家机构建造的沥青路面很少能像25年前那样持久。一些地区的寿命缩短了50-60%（2016年安大略省审计长年度报告），主要原因是实践和材料不佳。下降的原因是交通繁忙、异常天气（夏季/冬季极端温度）、机构工作人员缺乏知识导致使用不适当的规格，以及通过不正确和/或不负责任地使用某些回收材料来“绿化”我们的道路。在加拿大，价值约1200亿美元的道路处于一般、较差或非常差的状态（2016年加拿大基础设施报告卡）。******自2004年以来，我的小组制定了严格的规范标准，并在安大略省和国外的许多用户机构中实施了这些标准，并取得了很大的效果。我们现在需要研究如何使用有效的添加剂来减缓老化，以进一步减少开裂。******我们的短期目标是通过监测沥青中蜡、树脂和沥青质在常温和低温下的沉淀，了解如何更好地评估热可逆老化。在该领域，我们将首次使用创新的红外光谱方法来监测原油中蜡和沥青质的沉淀，以测量沥青中蜡和沥青质的沉淀。******我们将通过使用复杂的流变学方法测量经过不同程度化学老化的沥青的性质来研究凝胶的形成。确定胶凝开始的因素将比目前用于规格分级的因素更准确地衡量沥青何时容易开裂。******我们还将研究不可逆老化，为文献中关于沥青如何与氧气反应并随着时间变硬的长期争论提供证据。我们将在这个领域第一次使用氧-17核磁共振波谱，以及更传统的质子、碳-13和硅-29波谱，在一维和二维上。在可行的情况下，我们将使用富含同位素的保护群。******作为一个长期目标，我们将评估蜡抑制剂、分散剂、抗氧化剂和非常规基础沥青在减缓老化方面的使用，并使用光谱、热和流变分析技术来评估我们创新的抗老化添加剂的有效性。******这项研究计划将减少路面裂缝的困扰，并提供更可持续、更持久的道路基础设施。联邦、省级和市级政府，以及加拿大和国外的公众，将在未来的基础设施支出上实现巨大的节省，减少旅行延误，提高道路安全。嵌入式培训计划将为学生提供一套非常理想的可转移技能和受欢迎的知识，使他们在工作中具有竞争优势

Asphalt pavements constructed for municipal, provincial and national agencies today rarely last as long as they did 25 years ago. Some regions have seen lifespans shrink by as much as 50-60% (Annual Report, Auditor General of Ontario, 2016), largely due to poor practices and materials. The decline is due to heavier traffic, anomalous weather (extreme summer/winter temperatures), lack of knowledge among agency staff leading to the use of inadequate specifications, and the “greening” of our roads through the incorrect and/or irresponsible use of certain recycled materials. Across Canada, ~$120 billion-worth of roads are in fair, poor or very poor state (Canadian Infrastructure Report Card, 2016).******Since 2004, my group has developed rigorous specification standards and implemented them to great effect in numerous user agencies in Ontario and abroad. We now need to investigate how to mitigate aging with effective additives to further reduce cracking.******Our short-term objective is to understand how to better assess thermoreversible aging by monitoring the precipitation of waxes, resins and asphaltenes in asphalt at ambient and cold temperatures. In a first for this sector, we will use innovative infrared spectroscopy methods developed to monitor wax and asphaltene precipitation in crude oils to measure wax and asphaltene precipitation in asphalt. ******We will study gel formation by measuring properties for asphalt that has been chemically aged to varying degrees with sophisticated rheological methods. Factors defining the onset of gelation will provide a more accurate measure of when asphalt becomes prone to cracking than those currently used for specification grading.******We will also study irreversible aging to add evidence to longstanding disputes in the literature on how asphalts react with oxygen and harden over time. We will use oxygen-17 nuclear magnetic resonance spectroscopy, again for the first time in this sector, together with more conventional proton, carbon-13 and silicon-29 spectroscopy, in both one and two dimensions. We will use isotope enriched protective groups where feasible. ******As a long-term goal, we will evaluate the use of wax inhibitors, dispersants, antioxidants and unconventional base asphalts to mitigate aging, and use the spectroscopic, thermal and rheological analysis techniques to assess the effectiveness of our innovative anti-aging additives.******This research program will reduce cracking distress in pavements and provide a more sustainable, durable road infrastructure. Federal, provincial and municipal governments, as well as the general public in Canada and abroad, will achieve enormous savings on future infrastructure expenditures, reduce travel delays and improve road safety. The embedded training program will give students a highly desirable set of transferable skills and sought-after knowledge that will give them a competitive edge in the work force.**