Pavement performance of acidic fine aggregate-based asphalt mixture using geopolymer modified asphalt

The effective application of bitumen in pavement is hindered by its poor adhesion to acidic aggregates. This study investigates the potential of using geopolymer as an additive to improve the adhesion between bitumen and acidic aggregates. The geopolymer was characterized using scanning electron microscopy (SEM). Moreover, acidic fine aggregate-based asphalt mixtures were prepared using geopolymer modifier and compared with dehydrated geopolymer and cement. The pavement performance of acidic fine aggregate-based asphalt mixtures with different additives was analyzed. Results demonstrated that incorporating geopolymer into the bitumen significantly enhanced its pavement performance. Specifically, with the incorporation of 6% geopolymer to the bitumen, the residual stability and freeze–thaw tensile strength ratio (TSR) of the acidic fine aggregate-based asphalt mixture increased by 23.68% and 18.67%, respectively. Furthermore, the mixtures exhibited improved resistance to high-temperature deformation and low-temperature cracking. In conclusion, the results indicate that integrating geopolymer substantially enhances the performance of acidic fine aggregate-based asphalt mixtures, highlighting its potential as an effective additive in asphalt applications.