Effects of aging of bituminous mortar on the ravelling of porous asphalt surface layers, a literature study

摘要

A literature study on the effects of binder aging in relation to the raveling of porous asphalt pavement layers was carried out. Porous asphalt is cost effective solution in reducing traffic noise; however, because of its low density and high voids content, durability is a major problem limiting the service life of the pavement. In the Netherlands, about 70% of the surface failures in porous asphalt are related to raveling, i.e. loss of aggregates from the surface, and substantial cost is incurred for maintenance each year. Raveling occurs if the adhesion between the aggregates and the bituminous mortar is lost and/or the cohesion within the bituminous mortar is lost. The cohesive property is influenced by aging of the binder resulting in hardening of the bitumen increasing its susceptibility to failure under environmental and traffic stresses. In this study, it is intended to partly deal with the potential problem of raveling by addressing the causes for loss of cohesion in order to enhance the resistance to raveling. Increasing the binder thickness is seen as a feasible option to improve durability in porous asphalt.