Computer-Aided Procedure for Analysis of Effect of Gradation and Compaction Temperature in Asphalt Mix Design by Using DEM

Abstract

The procedure for asphalt mixture design includes determining grading, asphalt content, other volume properties, mechanical performance assessment, and moisture damage potential. This paper proposes a computational method to aid the design. A discrete element method (DEM) was involved to simulate the process of building voids and skeleton structures of an asphalt mixture with different grades. The method takes into account the mechanical properties or properties of the mixture, such as interaggregate contacts and local stability. A viscoelastic model is applied to simulate the contacts between asphalt binder and aggregates. The surface texture of aggregated particles could be considered in the interparticle contact model. In this study, the effect of various temperatures on the properties of hot mix asphalt (HMA) samples is evaluated in view of the need to maintain compaction temperatures. Again, to assess the effect of this parameter on different grades, two different grades are used, and the samples are compacted at different temperatures. Effects on the density, air voids, and flow of the asphalt mixture resulting from different compaction temperatures are analyzed based on a DEM simulated model. Observing the compaction temperature during the preparation of HMA can help to avoid the considerable variations in asphalt specifications.