Transition to Superpave Performance Grades in Western Canada

摘要

While most of North America has adopted Superpave? Performance Grading (PG) for paving asphalts, penetration-based specifications are still used in Western Canada. Heavy asphaltic crude oils available in Western Canada have historically produced an excellent quality paving asphalt. Therefore, there was little need for specification changes. However, increasing use of polymer modified asphalts and/or PG by some jurisdictions in Western Canada, cross-border technical specifications harmonization, and an ongoing need to certify paving grades in both specifications has initiated a move towards the Superpave PG specification. In recent years, some Western Canadian provinces have adopted the Superpave specification for paving grades. The adoption was relatively fast, building on the experience of the rest of the continent and Eastern Canada, specifically. The objective of this study is to compare asphalt qualities of a relatively large set of asphalts distilled from predominantly Western Canadian crude oils in both penetration-based and Superpave specifications. The ability of both specifications to predict fundamental rheological behaviour is analyzed. Moreover, the additional low temperature restrictions added to standard Superpave specification by some jurisdictions are analyzed and their relevance is discussed.