Work

Conduct an advanced numerical simulation investigation on the rutting performance of coal liquefaction residue asphalt mixture

Year: 2025

Type: article

Abstract: Coal liquefaction residue is a byproduct of coal-to-liquid technology, which is known to be detrimental to the ecological environment and human health. This study aims to investigate the impact of coal liquefaction residue on the rutting resistance of asphalt mixtures. The residue was substituted for fine aggregate on a volume basis, and a rutting model was developed using the discrete element method in PFC2D to analyze the behavior of mixtures under various temperatures and loads after the substitution. The study examines the influence of 0~4.75 mm coal liquefaction residue particles on the macroscopic rutting behavior by considering the displacement of fine particles and the distribution of force chains. The results indicate that the rutting development in coal liquefaction residue mixtures follows a power function growth pattern, divided into three stages: 0~10 min, 10~20 min, and 20~60 min, with the initial 0~20 min being critical for rutting formation. The particles in the coal liquefaction residue asphalt mixture exhibit strong self-organization adaptability, reducing the likelihood of stress concentration at rutting initiation. During rutting evolution, particles sized 0.6~2.36 mm contribute significantly to rutting deformation, while smaller particles (1.18~2.36 mm) are more susceptible to passive displacement due to compression and collision with larger particles (2.36~4.75 mm). However, in asphalt mortar with higher adhesive strength, the smaller 0.6–1.18 mm particles are more extensively coated by larger particles, leading to reduced displacement compared to the 1.18~2.36 mm particles. The 2.36~4.75 mm particles serve a macroscopic skeletal function, undertaking and transmitting microscopic contact forces. Numerical simulations confirm that replacing the 1.18~2.36 mm and 2.36~4.75 mm particles with ICLR single particle sizes, and the 0.6~1.18 mm and 1.18~2.36 mm particles with DCLR single particle sizes, are rational approaches. DCLR significantly enhances the high-temperature performance of asphalt mixtures compared to ICLR, aligning with the outcomes of macroscopic rutting tests.

Source: Frontiers in Materials

DOI: 10.3389/fmats.2025.1638678