Investigating mechanical characteristics of aggregate structure for road materials

Abstract

Aggregate structure plays a significant role in the pavement performance of road materials. However, there is a lack of fundamental understanding of mechanical characteristics and evolution characteristics of the aggregate structure in the existing research. To understand this complex structure, laboratory tests and numerical simulations using the discrete element method were used to investigate macroscopic mechanical properties of aggregate structure and microscopic aggregate contact forces, thus revealing the mechanical role of each size aggregate and evolution characteristics of the aggregate structure. Based on this, the specification gradations of road materials were optimised to build a strong aggregate structure. Laboratory tests and engineering application show that road materials using the proposed gradation can exhibit improved pavement performance and engineering effects.