Study of the Effect of Aggregate Geometry Characteristics on the Rheology of Asphalt Mortar Using Newly Developed Material Rheological Property Test Analyzer and Aggregate Image Measurement System

A new rheometer developed in the laboratory and the Aggregate Image Measurement System (AIMS) were used to study the effect of aggregate geometry characteristics on the rheological properties of asphalt mortar. AIMS was used to investigate the geometry characteristics (angularity index and Form 2-D) of two aggregates including steel slag and basalt. The results showed that steel slag had a better Form 2-D and angularity index, representing a better particle distribution and shape property. A material rheological property test analyzer was applied to evaluate the rheological properties of pure and styrene-butadiene-styrene (SBS)-modified asphalt and their asphalt mortars at 20 degrees C and 40 degrees C, and then the data were modeled through the simulation software. As a kind of rigid body, the addition of aggregate had a great influence on the rheological properties of asphalt. The experiment results indicated that, after the addition of aggregate or SBS, the rheological model of asphalt samples was still Burges model accompanied by the change of rheological parameters. As a kind of temperature-sensitive material, temperature was the most important factor for determining the rheological properties of asphalt. The addition of SBS promoted the elastic deformation of asphalt and restrained the viscous deformation of asphalt. The effect of aggregates with high Form 2-D and angularity index on the rheological properties of asphalt was weaker.