Effect of contact slip behaviour of particle on compaction characteristics of the asphalt mixture

Abstract

ABSTRACT To evaluate the contact slip behaviour of particle on compaction characteristics of the asphalt mixture, the relation between contact slip behaviour and compaction characteristic was analyzed. The specimen was molded by Superpave Gyratory Compactor, and the densification curve average slopes and densification energy index were adopted to evaluate the compaction characteristics of asphalt mixture. Based on the self-developed mineral contact tester and interface contact slip tester, the maximum slip force and the maximum slip shear stress were proposed to respectively evaluate the contact slip behaviours of the loose asphalt mixture and the formed asphalt mixture. The results show that the contact slip behaviour is well correlated with compaction characteristics. The maximum slip force of loose asphalt and the maximum slip shear stress can effectively evaluate the compaction characteristics of different compaction stages. The more the coarse aggregates, the stronger the contact effect among the particles, and the more difficult the asphalt mixture is to be compacted. AC-13 asphalt mixture has better workability than SMA-13 asphalt mixture and OGFC-13 asphalt mixture. The larger the nominal maximum aggregate size, the more energy the asphalt mixture needs to attach the target degree of compaction, and the better the anti-slipping deformation ability.