Research on the Warm Mixing Effect and Evaluation Method of WMA-DSBS Modified Asphalt

Background: Traditional SBS-modified asphalt consumes a large amount of energy during the production process. WMA-DSBS-modified asphalt can reduce the mixing temperature, which is crucial for reducing energy consumption. Objectives: The aim of this study was to reduce the mixing temperature as much as possible without compromising the performance of the asphalt mixture while saving energy consumption and protecting the environment. By evaluating the warm mixing effects of different warm mixing types applied to direct-to-plant SBS (DSBS) modified asphalt, as well as the changes in road performance after warm mixing DSBS modified asphalt mixture, reference opinions are provided for the dosage of warm mixing agents in engineering problems. Method: A comparison is made between DSBS-modified asphalt and warm mix DSBS-modified asphalt in terms of technical performance parameters. On the basis of the Brinell rotational viscosity test and the variable temperature compaction test, an index system for evaluating the modification effect of warm-mixed asphalt was developed. Result: The research results indicated that three different warm mixing agents have an enhancing effect on the temperature sensitivity, high-temperature performance, and low-temperature plastic deformation ability of asphalt in some temperature ranges. The viscosity of DSBS modified asphalt decreases with the increase of temperature before and after the addition of the three warm mix agents. During the temperature increase process, the viscosity reduction index K value changes from negative to positive; The dosage of warm mixing agent is negatively correlated with the porosity of WMA-DSBS modified asphalt mixture, and as the temperature increases, the porosity of the mixture will decrease. The performance value T shows an upward trend, improving its road performance. Conclusion: A reasonable dosage of warm mix agent can significantly reduce the mixing temperature, therefore WMA-DSBS modified asphalt plays an important role in reducing energy consumption.