Study on the filtration characteristics of asphalt mixtures containing different purification materials under multiple environmental impacts

As the modern highway network continues to expand, the leaching contamination from asphalt pavements may pose environmental risks. Meanwhile, the complex environmental interactions are key factors influencing the leaching behavior of pollutants from pavement structures. To investigate the influence of purification materials on pollutant release behavior under the coupled effects of multiple environmental factors (such as temperature, UV and pH), and to assess their environmental hazards, this study prepared asphalt mixtures by substituting mineral powder with diatomite, zeolite, and activated carbon. Laboratory leaching tests were conducted using a self-developed multi-factor environmental simulation device. The specimens were subjected to temperature and UV coupled aging, followed by leaching in acidic solutions with different pH values. Based on the experimental results, the leaching characterization of various pollutants under different environmental condition combinations were explored, and the influence of diatomite, zeolite, and activated carbon on the leaching behavior of pollutants was evaluated. Furthermore, an evaluation system for pollutants was established by fuzzy mathematics to comprehensively assess the purification efficiency of purification materials. The results indicated that elevated temperatures generally promoted the leaching of most pollutants (except for arsenic). Diatomite exhibited the highest purification efficiency for nutrient pollutants, while activated carbon showed the best purification efficiency for heavy metal pollutants. The overall purification efficiency rankings for mineral powder, diatomite, zeolite, and activated carbon were 8.4345, 6.0815, 5.9644, and 5.6713, respectively, with lower scores indicating higher efficiency, confirming that activated carbon demonstrating the best overall purification performance.