Asphalt concrete modification to improve flexible pavement performance in cold regions

沥青混凝土改性提高寒冷地区柔性路面性能

• 批准号: RGPIN-2019-05577
• 负责人: Hashemian, Leila
• 金额: $ 2.26万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=714284
• 关键词: Asphalt; concrete; modification; improve; flexible

Canada's road network is the seventh largest in the world, with a total length of 1.13 million km. The network is composed of 40% paved roadways and 60% unpaved roadways. More than 90% of the paved roads in Canada's network are composed of asphalt pavement. In cold regions such as Canada, pavement structures are subject to extremely low air temperatures and seasonal freeze-thaw cycles over the life cycle of the roadway, resulting in pavement distress, deterioration, and decreased service life. One promising possibility for increasing the performance of asphalt pavements at the high and low temperature ranges is modification of the asphalt to alter the physical properties of the asphalt mix. It is particularly important in the Canadian context to increase the resistance of asphalt mixes to thermal cracking. Low temperature cracking is the most prevalent distress in asphalt pavements in cold climates, resulting in substantial recurring expenditures for the rehabilitation of asphalt pavements. Recently, innovative materials such as nanoparticles have attracted increasing attention in the asphalt industry for use as asphalt concrete modifiers. Fibers have also been used to modify asphalt pavements for many years; however, there has been less attention to the incorporation of fibers in asphalt mixes to improve resistance to thermal cracking. The proposed research involves conducting laboratory investigations to understand the effects of the addition of nanomaterials and fibers on the properties of asphalt mixes at various temperatures and under freeze-thaw conditions. Laboratory testing will be done on unmodified and modified asphalt cement to investigate the impact of incorporation of nanomaterial on the rheological properties of the resulting asphalt cement. In addition, a series of prepared asphalt mix samples modified with nanomaterials, modified with fibers, and unmodified will be used to determine the physical and mechanical properties of the various asphalt mixes at different conditions and under freeze-thaw cycles. This comprehensive test data will be used to develop a model to predict creep compliance of modified asphalt mixes, which is a critical input for predicting the low temperature performance of asphalt pavements in mechanistic-empirical pavement design. This model, when validated, will allow the low temperature properties of asphalt mixes containing similar additives to be predicted, making it a useful tool for transportation authorities when designing pavements using modified asphalt mixes. The research will form the foundation for the establishment of a long--term research program in novel materials for road construction. It will also provide immediate economic and social benefits to Canada by improving the design, durability, and longevity of the asphalt materials used in roadway construction in cold climates.

加拿大的公路网是世界上第七大公路网，总长113万公里，其中40%是铺设的公路，60%是未铺设的公路。加拿大路网中90%以上的铺砌道路由沥青路面组成。在加拿大等寒冷地区，路面结构在道路的生命周期中受到极低的气温和季节性冻融循环的影响，导致路面破损、恶化和使用寿命缩短。在高温和低温范围内提高沥青路面性能的一个有希望的可能性是对沥青进行改性，以改变沥青混合料的物理性质。在加拿大，提高沥青混合料的抗热裂性尤为重要。低温开裂是寒冷气候下沥青路面最普遍的困扰，导致沥青路面修复的大量经常性支出。