Influence of direct coal liquefaction residue (DCLR) on the rutting behavior of asphalt mixture with the discrete element method

Document Type

Article

Publication Date

11-29-2024

Department

Department of Civil, Environmental, and Geospatial Engineering

Abstract

The research explores the influence of direct coal liquefaction residue (DCLR) as a fine aggregate on the rutting behavior of asphalt mixtures (AMs). Four AMs were prepared and modeled, namely AM (AM-0), AM with 2.36 mm DCLR (AM-2.36), AM with 1.18 mm DCLR (AM-1.18), and AM with 0.6 mm DCLR (AM-0.6). Firstly, the rutting depth and uplift height of AMs were analyzed. Results indicated that the rutting depth and uplift height of AMs increased with rising temperatures and loads. The order of rutting depth and uplift height of AMs at different temperatures and loads was: AM-0＞AM-2.36＞AM-1.18＞AM-0.6. This suggests that DCLR replacing fine aggregates improved the high-temperature performance of AMs, and DCLR replacing 0.6 mm fine aggregate was the best alternative. Moreover, the influence mechanism of DCLR on the rutting behavior was investigated by the force chain distribution and particle movement. The results showed that the rutting deformation was caused by the movement of 0.6–2.36 mm particles. Compared with AM-0, the chain distribution of AM-2.36 was uniform and sparse, and the movement of 0.6–2.36 mm particles in AM-2.36 was small. This was due to the composite modification effect of DCLR within the AM, which increased the bonding degree of asphalt mastics. This enhancement improved connectivity between aggregates, strengthened their load transfer capacity, and raised the AM's overall self-organizing adaptability. Finally, it was also found that DCLR as fine aggregates served dual roles within the AM, acting both as a skeleton and a filler.

Publication Title

Construction and Building Materials

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