Asphalt surface damage due to combined action of water and dynamic loading

Abstract Water ingress causes significant deterioration in asphalt surfaces. In this study, a novel laboratory test method has been developed to study the combined interaction of water-tire-pavement on the performance of four open graded and two gap-graded asphalt mixtures produced with 6 mm, 10 mm and 14 mm nominal maximum aggregate size. A dynamic load with a fixed frequency was applied while the surface was submerged with up to 2 mm water. The test continued until the specimens showed significant failures. Compared to dry condition testing, despite relatively good rutting performance, the appearance of surface crack was approximately seven times faster in open-graded mixtures tested in wet conditions, indicating accelerated deterioration due to the presence of water. The gap graded mixtures, on the other hand, showed better cracking resistance but inferior rutting performance. Finally, for same mixture tested in wet condition, mixtures with larger aggregate size showed more overall deterioration than mixtures with smaller size aggregates. The method has good potential to be implemented as a screening test for different types of mixes to study their water susceptibility due to combined action of tire-water-pavement.