Pavement engineering materials: Review on the use of warm-mix asphalt

Warm asphalt mixtures have been used worldwide aiming at saving energy and reducing emissions throughout the production process, without decreasing the in-service performance. This has been achieved with wax additives, chemical additives and foaming techniques. Benefits and drawbacks are mentioned in the literature for each process. This paper is a review of the main aspects involved in WMA technology, including constituent materials, mix design and mechanical performance issues, as well as technological specificities. Some discussion associated to life-cycle analysis is also considered. In the view of the literature review, it can be stated that WMA is a very interesting technology, able to contribute to achieve environmental objectives along with acceptable performance. WMA processes themselves require some additional complexity that must be considered by the players involved. (C) 2012 Elsevier Ltd. All rights reserved.