Effect of different filler substitution ratios on the service performance of asphalt mixtures: Using coal-based synthetic natural gas slag as substitute filler

Abstract

To investigate the effect of using coal-based synthetic natural gas slag (CNS) as a solid waste-based substitute filler on the service performance of asphalt mixtures, and validate its potential value as a substitute filler in asphalt pavements, thus the CNS powder (CNP) was selected as a solid waste-based substitute filler in this study, and then the variation trends of service performance of asphalt mixtures under different substitution ratios were evaluated by several mechanical tests. Subsequently, the grey relation analysis (GRA) model was conducted to explore the correlation between the different performance indicators and substitution ratios. The results indicate that the incorporation of CNP improved the high temperature performance of the mixture by 25.67–76.93 %, and increased its moisture stability by 15.44–26.99 %. Although the low temperature performance decreased by 0.54–6.19 %, it still met the required standards. Additionally, the incorporation of CNP enhanced the fatigue performance of the mixture by 3.39–7.64 %, while reducing its sensitivity to temperature and strain, and the dynamic modulus master curve constructed by using the Sigmoidal function accurately described the changes in the dynamic viscoelasticity of the mixture. A comparison study revealed that in different mixtures, the high temperature performance indicator consistently exhibited the highest correlation with filler substitution ratio, and this variation pattern was not influenced by filler type and substitution ratio.