Development of a calibration program for large-scale DEM simulation of hot mix asphalt

This paper presents a comprehensive Discrete Element Method (DEM) calibration program designed for optimal calibration of hot mix asphalt (HMA) in full-scale paving applications. The program allows for the calibration of various asphalt mixes and allows for studies such as how tamper stroke affects pre-compaction based on the calibrated HMA. The study identifies key pavement properties essential to the paving process, including pre-compaction resistance, flow behavior, and friction behavior between HMA and steel or asphalt surfaces, and details their laboratory-based evaluation methods. A contact model that incorporates realistic plastic deformation, adhesive forces, and multiple load cycles is presented in this research. Novel features include a two-clump particle shape system and a two-grain distribution for the grading curve. These parameters, combined with the contact model, facilitate the observation of particle orientations and segregations, ensuring an economical yet robust full-scale simulation. Validation included testing and calibration of three different asphalt mixes (Asphalt Concrete (AC) 11 DS, Stone Mastic Asphalt (SMA) 11 DS, and AC 16 BS). The results demonstrate the successful calibration of all relevant pavement properties using the prescribed methodology and settings. This study advances the understanding of HMA pavement properties and provides a practical framework for optimal calibration in full-scale paving scenarios.