Evaluation of asphalt properties in plant produced asphalt mixes

工厂生产的沥青混合料中沥青性能的评估

• 批准号: 530444-2018
• 负责人: Tighe, Susan
• 金额: $ 2.11万
• 依托单位: University of Waterloo
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=682991
• 关键词: Evaluation; asphalt; properties; plant; produced

The Ontario Ministry of Transportation (MTO) is responsible for the safety and quality of Ontario's highway network. 95% of this network is paved with hot mix asphalt (HMA): a material produced with heated stone, sand, or gravel bound together with asphalt cement, a product of crude oil. In Ontario, asphalt cement properties have been accepted based on performance grading to the American Association of State and Highway Transportation Officials (AASHTO) standards since the adoption of the Superpave technology in early 2000's. However, the aging protocols included in the AASHTO standard, which are intended to simulate the short term (production and placement) and longer term (in service) oxidative aging of asphalt cement, have been shown to not correlate with field aging. In 2009, the Bituminous Section of the Materials Engineering Research Office (MERO) of the MTO added new tests to provide better characterization of asphalt materials and prediction of asphalt pavement performance in Ontario. A study was conducted to evaluate the new tests and how well they correlate with performance - the study concluded that correlation to field for both the current and new tests could be improved, if field aging can be better replicated in the lab. Nonetheless, the new test methods have been adopted by MTO for acceptance. Testing is carried out on asphalt cement samples collected from HMA producers' asphalt tanks. In addition, some municipalities in Ontario have further modified this specification, applying them to recovered asphalt cement from HMA. That is, the asphalt binder is removed or extracted from the aggregates in the HMA mix by using a solvent, then the asphalt is recovered from the solution for testing. There are concerns with the appropriateness of acceptance criteria based on recovered asphalt cement, because research has shown that the extraction and recovery process can impact the asphalt cement properties, and there is no understanding of how the recovered asphalt properties compare to the original virgin asphalt. Accurate material characterization is important for engineers and owners to predict performance. Therefore, the overall objective of this research is to provide a framework for characterizing of asphalt cement and HMA by: firstly, comparing current laboratory aging protocols to field aging of asphalt cement; and second how the measured properties of the asphalt cement and HMA correlate to performance.The study will also include a review of test results reported by various industry testing labs, to assess the range in test results between labs, to understand the testing variability associated with material characterization of recovered asphalt.

安大略交通部（MTO）负责安大略高速公路网的安全和质量。这个网络的95%是用热拌沥青（HMA）铺成的：一种由加热的石头、沙子或砾石与沥青水泥结合在一起制成的材料，沥青水泥是原油的一种产品。在安大略，自从2000年初采用Superpave技术以来，沥青水泥性能已经基于美国州和公路运输官员协会（AASHTO）标准的性能分级而被接受。然而，AASHTO标准中包含的老化协议旨在模拟沥青水泥的短期（生产和浇筑）和长期（使用中）氧化老化，已被证明与现场老化无关。 2009年，MTO材料工程研究办公室（MERO）的沥青部分增加了新的测试，以提供更好的沥青材料特性和预测安大略的沥青路面性能。进行了一项研究，以评估新的测试以及它们与性能的相关性-研究得出的结论是，如果可以在实验室中更好地复制现场老化，则可以改善当前和新测试与现场的相关性。 尽管如此，新的测试方法已获海事处接纳。对从HMA生产商的沥青罐中收集的沥青水泥样品进行测试。此外，安大略的一些市政府还进一步修改了该规范，将其应用于从HMA中回收的沥青水泥。也就是说，通过使用溶剂从HMA混合物中的集料中除去或提取沥青粘合剂，然后从溶液中回收沥青用于测试。 人们对基于回收沥青胶结料的验收标准的适当性表示担忧，因为研究表明，提取和回收过程会影响沥青胶结料的性能，并且不了解回收沥青与原始沥青的性能如何比较。准确的材料表征对于工程师和业主预测性能非常重要。因此，本研究的总体目标是提供一个表征沥青水泥和HMA的框架：首先，比较目前的实验室老化方案与沥青水泥的现场老化;第二，沥青水泥和HMA的测量性能如何与性能相关。该研究还将包括对各行业测试实验室报告的测试结果的回顾，评估实验室之间测试结果的范围，了解与回收沥青材料特性相关的测试可变性。