Assessing the stripping properties of granite aggregates in bituminous mixtures

The properties of aggregates in asphalt pavements are an important influence on the service lives of pavements. Aggregates should be covered by bitumen film and the film should remain stable under the effects of water and traffic loads. We studied the stripping behavior of eight different types of granitic rock in bituminous mixtures. First, we conducted petrographic examinations and mineralogical and chemical analyses of the samples. Surface roughness and surface tension tests were then performed. Finally, stripping and pull-out tests were conducted on the granite aggregates. We found that the stripping caused by water is dictated by mineralogical and chemical composition and surface tension, whereas the stripping caused by traffic loads is controlled by mineralogical and chemical composition and the surface roughness of granite aggregates.