Evaluation of rutting performance of asphalt mixture based on the granular media theory and aggregate contact characteristics

Abstract

Based on digital image processing technology, this paper calculates the number of contact points and inclination of coarse aggregates. The asphalt pavement analyzer (APA) is applied to evaluate the rut depth of AC-13F, AC-13C, SMA-13 and MLB-13 asphalt mixtures added different kinds of asphalt. The granular media theory and uniaxial penetration test are introduced to find out the relationship between the number of contact points and shearing strength of mixture; results prove that the number of contact points can logically evaluate the high-temperature stability of mixtures. And both uniform strain model and static model are well predicting the shear modulus. Test results indicate that the high-temperature stability of asphalt mixtures can be defined via the initial number of contact points and variation of inclination. Adoption of T SP (the softening points of asphalt) as model variable is better to describe the relationship among contact points, asphalt performance and rut depth than adoption of rut factor G*/sinδ. The prediction model adopting rut factor G*/sin δ as model variables needs further study and validation. We define N opt as the optimal contact point number and N min as the minimum contact point number, which are supposed to be applied into the mixture design as references for gradation selection.