Synergistic influence of aging and moisture on performance of warm mix asphalt

Abstract

In this study, the influence of aging and moisture on the two different mechanical behaviors of warm mix asphalt was studied. The cracking and permanent deformation resistance were assessed in terms of tensile strength and flow number computed using a three stage model respectively. The influence of temperature on the tensile strength and both stress and temperature levels on the permanent deformation response of aged and moisture conditioned warm mix asphalt were investigated. Results show that moisture and increase in temperature had a negative impact on the tensile strength of warm mix asphalt while aging had a positive impact. However, the variation in tensile strength of mixtures was strongly related to variation in percent air voids. Aging and interestingly moisture conditioning were found to increase the resistance to permanent deformation of warm mix asphalt. Permanent deformation behavior of moisture conditioned samples was further studied to assess the impact of saturation. Results showed that the presence of moisture in samples increases the permanent deformation resistance. From the statistical analysis it was found that both the individual and interaction of aging and moisture had a significant effect on the tensile strength and flow numbers.