Investigation of the effects of environmental factors on pavement properties and performance in cold regions

加拿大的道路基础设施系统是全国经济发展和休闲旅游的重要组成部分。研究表明，环境因素是道路基础设施损坏的主要原因。加拿大大多数省和地区的路面结构受到极低气温和冻融循环的影响，这会导致路面退化和使用寿命降低。冻胀和融化减弱是冻融循环产生的两个主要问题。对于寒冷地区的道路系统来说，这些问题变得更加重要，因为在这些地区，预计未来将发生气候变化导致的冻融周期增加。人们已经进行了大量的研究来评估环境因素对温暖和温和气候地区路面材料行为的影响，然而，对寒冷地区气候(如冻融循环)对路面结构的严重影响还没有进行同样程度的研究。 这项研究的主要目的是通过一个综合的实验室、现场和网络研究计划来表征和量化环境因素对寒冷地区路面材料和性能的影响。该实验室计划将通过模拟几种环境情景来表征几种类型的土壤。将开发融化弱化指数和预测模型来表征路面材料的行为。现场监测方案和网络研究将提供真实的数据，以促进对实验室结果的评估。这项研究的知识和结果将有助于加拿大公路机构改进他们现有的路面设计，并促进最近开发的力学经验路面设计指南(MEPDG)的实施。预计这项研究的结果将改善加拿大寒冷地区的路面使用寿命和质量。

The Canadian road infrastructure system is an important component of economic development and recreational travel across the nation. Studies have shown that environmental factors are major causes of road infrastructure damage. Pavement structures in most Canadian provinces and territories are subject to extreme low air temperatures and freeze-thaw cycles, which result in pavement deterioration and lower service life. Frost heave and thaw-weakening are two of the major problems that occur as a result of freeze-thaw cycles. These issues become more important for road systems in cold regions where increased freeze-thaw cycles as a result of climate changes are expected to happen in the future. Considerable research studies have been conducted to assess the impact of environmental factors on pavement materials behavior in warm and moderate climatic regions; however, the severe effects of cold region climate, such as freeze-thaw cycles, on pavement structures have not been investigated to the same extent. The main objective of this research is to characterize and quantify the effects of environmental factors on pavement materials and performance in cold regions using a comprehensive laboratory, field, and network research program. The laboratory program will characterize several types of soils via simulation of several environmental scenarios. Thaw-weakening indices and prediction models will be developed to characterize pavement materials behavior. The field monitoring program and network study will provide authentic data to facilitate the evaluation of laboratory findings. Knowledge and results from this study will help Canadian highway agencies to improve their existing pavement design as well as to facilitate the implementation of the recently developed Mechanistic Empirical Pavement Design Guide (MEPDG). It is anticipated that results from this research will improve pavement service life and quality in Canada's cold regions.