Development of a laboratory ageing method for bitumen in porous asphalt

Abstract

Generally porous asphalt has lower durability than commonly used dense asphalt mixtures. Loss of aggregates from the pavement surface, called raveling, is the most common form of distress in porous asphalt. There are several factors that contribute to the accelerated failure or raveling of porous asphalt and among them ageing is believed to be the main reason for raveling failure of porous asphalt. It increases the chance of damage development because of applied traffic loading and thermal stresses at low temperature. During design phase of pavement, it is imperative to know beforehand what the properties of the pavement will be after field ageing. This will help to minimize maintenance cost due to premature failure and to increase the confidence level of the design of the pavement. It is evident; therefore, that there is a need for accelerated laboratory ageing method that can simulate binder properties similar to that of field aged binder. As a result this study was initiated and the objective was to develop a laboratory ageing procedure which is able to mimic binder properties of 7 years field aged porous asphalt pavement.