Effect of warm mix additives on asphalt cement, asphalt rubber and asphalt mixture quality and durability

本研究旨在探讨温拌沥青混合料技术对沥青混合料质量和耐久性的影响。在过去的十年中，安大略交通部（MTO）已经开始了几个提高可持续性的计划。最近引进的温拌沥青混合料有助于在更低的温度（30 C-50 C）下压实。去年，MTO投放了220，000吨温拌混合料，预计未来几年这一数量将大幅增加。使用沥青橡胶可以回收大量橡胶轮胎，并有可能显着改善生命周期成本。作为支持，MTO使用废橡胶粉改性剂进行了大量试验。安大略轮胎管理局（OTS）和MTO现在致力于在2013年建造三个温拌沥青橡胶试验。通过温拌促进的较低温度提供了沥青橡胶特别期望的几个优点：减少排放，降低能源成本，促进更长的运输距离，以及晚季摊铺。然而，缺乏专门评估此类添加剂对质量和耐久性影响的研究。我们将质量定义为沥青水泥抵抗车辙、疲劳、热开裂和水分损害的能力。耐久性被定义为在长使用寿命内保持所需性能的能力。我们假设，各种添加剂（温混料和橡胶）的质量和耐久性存在明显差异，但尚未得到用户和生产商的认可。加拿大大部分地区的寒冷气温可能会产生不必要的早期困扰，导致未来的成本，使继续使用潜在的有益概念在寒冷的气候铺路不可持续。研究结果将有助于沥青行业选择温拌和沥青橡胶技术，在长期成本和风险控制方面提供最大的利益。该项目将在沥青科学和工程的最新方面培训一些研究生和本科生。与温拌添加剂与沥青水泥的相互作用有关的研究结果也可能在石油加工等其他领域有潜在的应用。

The proposed research is to investigate the effect of warm mix asphalt technologies on asphalt quality and durability. Over the past decade, the Ontario Ministry of Transportation (MTO) has embarked on several programs that improve sustainability. The recent introduction of warm mix asphalt facilitates compaction at much reduced temperatures (30C-50C). Last year MTO placed 220,000 tonnes of warm mix and this amount is expected to increase significantly in years to come. The use of asphalt rubber allows for the recycling of large quantities of rubber tires and has the potential to significantly improve lifecycle costs. In support, MTO has constructed numerous trials using crumb rubber modifier. The Ontario Tire Stewardship (OTS) and MTO are now committed to the construction of three warm mix asphalt rubber trials in 2013. The lower temperatures facilitated by warm mixes provide several advantages that are particularly desirable for asphalt rubber: reduced emissions, reduced energy costs, facilitation of longer haul distances, and late season paving. However, there is a dearth of studies that specifically assess the effect such additives have on quality and durability. We define quality as the ability of an asphalt cement to resist rutting, fatigue, thermal cracking, and moisture damage. Durability is defined as the ability to maintain desired properties over a long service life. We hypothesize that there will be pronounced quality and durability differences for the various additives (warm mix and rubber) that have yet to be recognized by users and producers alike. Cold temperatures in much of Canada could produce unwanted early distress resulting in future costs, making the continued use of potentially beneficial concepts in cold climate paving unsustainable. The research results will help the asphalt industry with the selection of warm mix and asphalt rubber technologies that provide the greatest benefit in terms of long term cost and risk control. The project will train a number of graduate and undergraduate students in the latest aspects of asphalt science and engineering. The findings related to the interaction of warm mix additives with the asphalt cement could also have potential applications in other areas such as petroleum processing.