Design of low chloride salt deicing filler based on SCD and optimization of dosage using NSGA-II algorithm

Winter road snow melting is an important issue for traffic safety in cold regions. Traditional snow-melting materials, due to their high chloride content, cause severe corrosion to the environment and infrastructure. To solve this issue, a new type of Low Chloride Salt Snow-Melting Filler (LCSMF) was developed in this study, and its optimal preparation process and dosing amount were determined through system optimization and performance evaluation. First, the best carrier and the best hydrophobic modifier were determined by material comparison, and the modification conditions were optimized: modification temperature, modification time, and modifier dosage. Secondly, the active ingredient of snow melting was optimized by orthogonal experiment, and the optimal ratio of the active ingredient was determined by Simplex Centroid Design (SCD) test using Minitab software. The optimized salt-storing filler was incorporated into the asphalt mixture by isovolumetrically replacing the mineral powder, and its comprehensive performance was evaluated by snow melting performance (ice-road bond test) and pavement performance (high temperature stability, low temperature crack resistance, water stability test). The results showed that the salt-storing filler significantly deteriorated the low-temperature crack resistance and water stability, which could be defined as performance shortcomings. Based on this finding, snow-melting performance, low-temperature crack resistance, and water stability were selected as key indicators to construct a multi-objective optimization model. The NSGA-II algorithm was used to generate the Pareto front, and the ideal point method (TOPSIS) was employed to select the solution closest to the ideal point from the Pareto front. The optimal dosage was finally determined: in the AC gradation, the salt-storing filler could replace 99.9% of the mineral powder, and in the SMA gradation, it could replace 86.7% of the mineral powder. This study provides an efficient and environmentally friendly new material for winter road snow melting and offers a scientific basis for its practical application.