Effects of compaction on the initiation and propogation of top-down cracks and the shear properties of asphalt mixes

申请人在过去20年的研究工作已经确定，沥青路面早期劣化的一个主要原因是施工引起的裂缝。 这一结论在一种全新的压实设备--沥青多联式压路机（AMIR）的开发中得到了证实。 AMIR压实机可防止施工过程中出现此类裂缝。 早期劣化的第二个主要原因是由于在交通负荷下剪切刚度不足而导致的沥青混合料的推挤。 在另一项突破性的工作中，申请人开发了一种新设备，即原位剪切刚度测试（InSiSST）。 该设备测量沥青路面的剪切性能，而不需要耗时，昂贵，和不具代表性的实验室分析。 这项研究是在这两项重要成果的基础上进行的。 研究计划包括四个主要任务：（1）实验研究，包括加拿大和海外试验段的现场和实验室测试，（2）理论研究，（3）根据先前研究结果开发预测模型，（4）短期和长期性能评估。 研究计划包括使用AMIR和钢辊（并排）进行现场测试，以及现场和实验室测试，以比较其长期性能。 此外，还将进行理论研究，以根据可靠的现场和实验室数据开发预测路面行为和性能的统计模型。 路面性能的建模将在项目的五年期间继续发展。 拟议工作的最重要影响是开发加拿大技术，处理作为国家基础设施重要组成部分的全球市场。 该研究将有助于改善路面性能、压实和评价技术。

The research work of the applicant over the past 20 years has established that one major cause of the early deterioration of asphalt pavements is construction-induced cracks.  This conclusion was proved when a fundamentally new compaction device, Asphalt Multi-Integrated Roller (AMIR), was developed.  The AMIR compactor prevents such cracking during construction.  A second primary cause of early deterioration is shoving of the asphalt mix as a result of insufficient shear stiffness under traffic loading.  In another ground-breaking effort, the applicant developed a new equipment, In-Situ Shear Stiffness Test (InSiSST).  This facility measures the shear properties of asphalt pavements "on-the-road" without the need for the time consuming, costly, and unrepresentative laboratory analysis.   The proposed research builds upon these two important achievements.  The research plan consists of four main tasks: (1) experimental investigation including field and laboratory testing from test sections in Canada and overseas, (2) theoretical investigation, (3) development of prediction models based on the results of the preceding investigations, and (4) evaluation of short and long-term performance.  The research plan includes the construction of field tests using the AMIR and steel rollers (side by side), and field and laboratory tests to compare their long- term performance.  In addition, a theoretical investigation will be carried out to develop statistical models for predicting pavement behaviour and performance based on reliable field and laboratory data.  The modeling of pavement performance will continue to evolve over the five-year duration of the project.  The most significant impact of the proposed work is the development of a Canadian technology dealing with a universal market that is an important component of the nation's infrastructure.  The proposed research is expected to improve pavement performance, compaction, and evaluation technologies.