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: 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=697727
• 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.

安大略省交通部 (MTO) 负责安大略省高速公路网的安全和质量。该网络的 95% 是用热拌沥青 (HMA) 铺设的：一种由加热的石头、沙子或砾石与沥青水泥（原油产品）粘合在一起制成的材料。 在安大略省，自 2000 年初采用 Superpave 技术以来，沥青水泥性能已根据美国国家和公路运输官员协会 (AASHTO) 标准的性能分级得到认可。然而，AASHTO 标准中包含的老化协议旨在模拟沥青水泥的短期（生产和放置）和长期（使用中）氧化老化，但已被证明与现场老化无关。 2009 年，MTO 材料工程研究办公室 (MERO) 的沥青部门增加了新的测试，以更好地表征安大略省的沥青材料并预测沥青路面性能。进行了一项研究来评估新测试及其与性能的相关性 - 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，则可以改善当前测试和新测试与现场的相关性。 尽管如此，新的测试方法已被 MTO 采用并接受。对从 HMA 生产商的沥青罐采集的沥青水泥样品进行测试。 此外，安大略省的一些市政府还进一步修改了该规范，将其应用于从 HMA 回收的沥青水泥。即，使用溶剂从HMA混合物中的骨料中去除或提取沥青结合料，然后从溶液中回收沥青用于测试。 人们担心基于回收沥青水泥的验收标准的适当性，因为研究表明提取和回收过程会影响沥青水泥的性能，并且不了解回收的沥青性能与原始沥青的比较如何。 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通过以下方式提供表征沥青水泥和 HMA 的框架：首先，将当前的实验室老化协议与沥青水泥的现场老化进行比较；其次，测量的沥青水泥和 HMA 特性与性能之间的关系如何。 该研究还将包括对各个行业测试实验室报告的测试结果的审查，以评估实验室之间测试结果的范围，以了解与回收沥青的材料特性相关的测试变异性。