Innovative materials and test methods for long-life asphalt pavements

我们研究的短期目标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。第二个目标将是开发新的测试方法来模拟服役中的化学老化。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。今天，虽然几乎所有的润滑油都含有与降凝点剂类似的物质，但沥青中不存在这样的添加剂。从油砂项目中提取的大量低质量沥青即将生产，这意味着这项研究有一定程度的紧迫性。第二个领域将侧重于开发新的路线，使丁苯聚合物与沥青兼容。化学方法将被设计成促进沥青接枝到聚合物骨架上，而不是交联聚合物，这是已知的会导致性能恶化。我们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三级蠕变阶段。这一变形阶段主要发生在旧路面上，包含断裂成分。我们的最后一个研究领域涉及改进老化试验的发展。目前的实验室方案不能复制粘合剂在使用过程中化学老化的方式；因此，这些协议需要改进。如果我们成功地开发出更多的抗破坏沥青，对加拿大的好处是巨大的。有140多万公里的双车道公路，目前每年的维修费用超过100亿美元。重要的是，通过如此巨大的投资，更好地了解沥青的全部机械性能潜力（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使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.