Simulation study on asphalt fume diffusion during pavement laying in long tunnels

Abstract

Tunnel asphalt pavement construction cause pollutant accumulation, presenting health risks. Considering the production principles of asphalt fumes, this study accurately calculates asphalt fumes’ release intensity based on fume source type classification and model optimization. Using the Large Eddy Simulation method, we studied the asphalt fumes’ diffusion behavior and concentration in working areas. The results indicate that tunnel ventilation substantially reduces the concentration of asphalt fumes within the working zones. The most pronounced decrease occurs when the wind speed increases from 0.5 m/s to 1.0 m/s. The average fume concentration drops below 5 mg/m3 at wind speeds exceeding 2 m/s. The average asphalt fume concentration during paving in a downwind direction is higher than in an upwind direction. The mixture’s temperature and state largely impact the intensity of the fume source. Lowering the temperature by 30℃ can substantially diminish the asphalt fumes’ concentration in the working area, effectively controlling the health risks to workers.