Enhancement mechanism of oil shale waste filled asphalt mixtures based on oil adsorption and storage behavior

Oil shale waste, which contains casein, asphaltene , and other organic matter, possesses a well-developed pore structure and potential oil storage properties. However, these properties and its role in real-time adjustment of asphalt components have often been overlooked when utilizing oil shale waste for pavement filling. To address this, this study explored the performance enhancement mechanism of oil shale waste filled asphalt mixture by examining the percolation interaction between oil shale waste and asphalt using both physical probing and chemical simulation methods. Chemically, molecular dynamics simulations were conducted to study the interaction of asphalt with different oxides and the diffusion pattern of asphalt components at the interface. Physically, industrial CT scanning was used to visualize the distribution of asphalt within the pore structure of the waste, allowing for the summation of interaction patterns. The test results revealed that the interaction force repulsion between oil shale waste and asphalt is 16.85 % smaller than that between limestone and asphalt. The adsorbed asphalt film thickness of oil shale waste was found to be higher than that of limestone, with asphalt infiltrating into the pore space . Specifically, the adsorbed asphalt film thickness of oil shale waste was 21.68 % thicker than that of limestone, the adsorbed asphalt volume was 85.49 % larger, and the number of adsorption sites was 35.91 % more. These findings indicate that oil shale waste has a stronger oil adsorption and storage capacity, highlighting its potential for improving the properties of asphalt mixtures. • The oil shale waste was utilized to replace 4.75 mm fine aggregate in asphalt mixtures. • The TLC-FID test was used to analyze the adsorption of asphalt components on the oil shale surface. • The interaction energy between oil shale waste and asphalt was calculated by MD simulation. • The industrial CT was employed to construct the distribution of asphalt in the waste slag pores.