Workability and Performance of Polymer-modified Asphalt Aggregate Mixtures in Cold Regions

• Published in: The international journal of pavement engineering Vol. 4; no. 1; pp. 25 - 36
• Main Authors: Zubeck, Hannele K., Raad†, Lutfi, Saboundjian‡, Stephan, Minassian¶, George, John Ryer§, P.E.
• Format: Journal Article
• Language: English
• Published: Taylor & Francis Group 01-03-2003
• Subjects: Cold region; Low-temperature cracking; Polymers; Rutting; Specifications
• DOI: 10.1080/1029843031000097535
• EISSN: 1477-268X
• ISSN: 1029-8436

Polymer-modified asphalts have been used in cold regions for about 15 years to address problems with rutting, cracking and premature aging. However, due to the cold climate and remote locations construction problems are sometimes encountered. This paper deals with workability of polymer-modified mixes while assuring that the desired pavement performance is achieved.
The construction problems arise with possible poor compatibility of the base asphalt and the polymer, the storage stability of the asphalt-polymer mixture and cold construction temperatures. These properties were tested for several polymer-modified asphalt combinations. A set of products that were compatible, storage stable and had improved temperature susceptibility were selected and further tested in asphalt-aggregate mixtures. A Georgia Wheel rutting test and the Thermal Stress Restrained Specimen Test were performed. A questionnaire study was also conducted to collect experiences and specifications in cold regions.
Tests indicate that polymer-modified asphalts should always be the end result of an extensive product development program. The polymer modification improved the performance of all base asphalts in certain polymer-asphalt combinations. However, some otherwise acceptable binders smoked excessively when the temperature was elevated to the recommended mixing temperature. This issue warrants further investigation.