Predicting stripping and moisture induced damage of asphalt concrete prepared with polymer modified bitumen and hydrated lime

Many highway agencies have been experiencing premature failures that decrease the performance and service life of pavements. One of the major causes of premature pavement failure is the moisture damage of the asphalt concrete layer. Many variables affect the amount of water damage in the asphalt concrete layer such as the type of aggregate, bitumen, mixture design and construction, level of traffic, environment, and the additive properties that are introduced to the bitumen, aggregate or bitumen-aggregate mixture. This study is aimed to determine the effect of additives Such as hydrated lime as well as elastomeric (SBS) and plastomeric (EVA) polymer modified bitumen (PMB) on the stripping potential and moisture susceptibility characteristics of hot mix asphalt (HMA) containing different types of aggregate (basalt-limestone aggregate mixture and limestone aggregate). The stripping properties and moisture susceptibility characteristics of the samples have been evaluated by means of captured images and the Nicholson stripping test (ASTM D 1664) as well as the modified Lottman test (AASHTO T 283), respectively. The results indicated that hydrated lime addition and polymer modification increased the resistance of asphalt mixtures to the detrimental effect of water. Moreover, it was found out that samples prepared with SBS PMB exhibited more resistance to water damage compared to samples prepared with EVA PMB. (C) 2008 Elsevier Ltd. All rights reserved.