Innovative materials and test methods for long-life asphalt pavements

我们研究的短期目标将是开发创新的添加剂和设计，以防止沥青因低温和疲劳破坏而断裂。第二个目标是开发新的试验方法，以模拟使用中的化学老化。长期目标将是确保政府和工业界接受这些改进，以实现更可持续的基础设施。我们的研究将集中在几个新的领域。我们的主要兴趣是设计新的共聚物，降低沥青在低温下的屈服应力。如今，沥青中不存在此类添加剂，尽管几乎所有润滑剂都含有与倾点下降剂类似的材料。从油砂项目中提取的大量低质量沥青即将生产，这意味着这项研究具有一定的紧迫性。第二个领域将侧重于开发新的路线，使苯乙烯-丁二烯聚合物在沥青中相容。将设计化学方法以促进沥青接枝到聚合物主链上，而不是使聚合物交联，已知交联会导致性能劣化。我们的研究的第三个领域将调查韧性，界面强度和填料尺寸如何影响沥青的第三蠕变阶段。这种变形阶段在旧路面中占主导地位，涉及断裂成分。我们的最后一个研究领域涉及改进老化测试的开发。目前的实验室方案没有复制粘合剂在使用中化学老化的方式;因此需要改进这些方案。如果我们成功地开发出更耐破坏的沥青，对加拿大的好处是巨大的。有超过140万双车道等效公里的道路，目前每年的维修费用超过100亿美元。重要的是，在如此巨大的投资下，充分的机械性能潜力（例如，模量、韧性、屈服应力、变形）。我们的研究将继续为实现这一目标做出重要贡献。在我的实验室获得的培训将允许学生在沥青材料部门或密切相关的聚合物，粘合剂和涂料行业找到工作。

The short-term objective of our research will be to develop innovative additives and designs to prevent fracture in asphalt due to low temperature and fatigue distress. A secondary objective will be to develop new test methods to simulate chemical aging in service. The long-term objective will be to secure the acceptance of these improvements by government and industry to achieve a more sustainable infrastructure. Our research will focus on several new areas. Our primary interest is to design new copolymers that lower the asphalt yield stress at low temperatures. Today, no such additives exist for asphalt, although virtually all lubricants contain similar materials as pour point depressants. The imminent production of large quantities of lower-quality asphalt derived from oil sands projects means that there is a degree of urgency to this research. A second area will focus on the development of new routes to make styrene-butadiene polymers compatible in asphalt. Chemical methods will be designed to promote grafting of asphalt onto the polymer backbone rather than crosslinking the polymer, which is known to cause a deterioration of properties. A third area of our research will investigate how toughness, interfacial strength, and filler size affect the tertiary creep stage in asphalt. This deformation stage, which is predominant in old pavements, involves a fracture component. Our final area of research relates to the development of improved aging tests. Current laboratory protocols do not replicate the way in which binders chemically age in service; hence improvements are needed in these protocols. If we succeed in developing more failure-resistant asphalts the benefits to Canada are significant. With over 1.4 million two-lane equivalent kilometers of roads, current annual repair costs amount to over $10 billion. It is important that, with such an enormous investment, the full mechanical property potential (e.g., modulus, toughness, yield stress, deformation) of asphalt is better understood. Our research will continue to make important contributions toward this goal. Training obtained in my laboratory will allow students to find jobs in the asphalt materials sector or in closely related polymer, adhesives, and coatings industries.