Study on betel nut fiber enhancing water stability of asphalt mixture based on response surface method

Abstract

In recent years, there has been an increasing interest in waste fiber reinforced asphalt mixes. Waste betel nut fiber (BNF) can improve the tensile strength of asphalt mixture, while the hydrophilic groups on its surface can reduce its water stability. Therefore, this study investigated the effect of alkali-treated BNF on the water stability performance of asphalt mixtures. The effects of shear time, fiber content, and asphalt aggregate ratio on the water stability of BNF-enhanced asphalt mixtures were investigated separately by response surface methodology (RSM). The road performance of the RSM method with optimal solution and without fiber, fiber without alkali treatment, and fiber without shear was also compared. The results showed that under the AC13 gradation, the optimal solutions of multi response variables are fiber content of 0.2561%, fiber shear time of 12.78 min and asphalt aggregate ratio of 5.82%. The corresponding predicted Rdry value is 1.48 MPa, Rsaturated value is 1.27 MPa and TSR value is 88.41%. The final test results are within the 95% confidence interval, and the prediction model has good reliability. The optimal solution has the best low-temperature flexural strength and water stability. This study helps to promote the application and promotion of BNF in road construction.