Mechanical Evaluation of Concrete Bridge Deck Pavement Systems

Asphalt pavement systems for concrete bridge decks must not only comply with requirements from traffic and environmental exposure but also provide protection of the concrete structures against corrosive attacks from water or deicing agents. These multifunctional expectations are major challenges not only from the material side but also from the experimental side as to the evaluation of the right test methods for assessing the mechanical behavior of the whole multi-layer pavement system. In this article, the results of a research project comparing different asphalt pavement systems for alpine regions are presented. These systems consist of hot rolled and mastic asphalt for wearing and protection layers placed on waterproofing systems with polymer bitumen sheets, liquid polymer, and mastic asphalt. The study revealed both the mechanical differences between the different systems and the weaknesses or strengths of different mechanical tests, clearly demonstrating that one has to be careful in interpreting seemingly contradictory results of different test methods. In particular, it was interesting to see that the rutting assessment for some systems differs between cyclic compression tests and rutting tests conducted with a model mobile load simulator.