Abstract. To study the mechanical behavior of crushed rock aggregate, a series of largescale direct shear tests were conducted. Then the particle flow model was established with PFC3D (Particle Flow Code 3D) to analyze the micromechanical properties, including the distribution of contact forces and displacement vectors.
A model road was constructed in a laboratory. The road consisted of asphalt over a crushed rock base and a silty sand and gravel subbase. The silty sand and gravel were placed in a very loose state to simulate a thawweakened, poorquality subbase. The water table was kept at 152 mm (6 in.) below the bottom of the asphalt.
Crushed Rock 11/4" minus. Rock screened to 1 1/4". Has fines in it. Used as a sub base for driveways and parking areas. 42. Crushed Rock 11/4" clean. Typically used for drainage purposes and firming up soft or muddy conditions. It works well for pathways and doesn't roll like smooth drain rock. Contains no fines or minus material.
