Optimization Design and Mechanical Performances of Plant-Mix Hot Recycled Asphalt Using Response Surface Methodology

This study aimed to explore the influence of material design parameters on the physical and mechanical properties of recycled asphalt. A Box-Behnken design was employed to determine the optimal preparation scheme for 17 groups of recycled asphalt. The effects of styreneic methyl copolymer (SMC) regenerant content, styrene-butadiene-styrene (SBS)-modified asphalt content, and shear temperature on the mechanical properties of recycled asphalt were analyzed using conventional and high/low-temperature rheological tests. The optimal processing parameters were determined by a response surface model based on multiple response indexes. The results revealed that the SBS-modified asphalt content had the most significant effect on the penetration of recycled asphalt. An increase in SMC regenerant content led to a gradual decrease in the rutting factor, while SBS-modified asphalt content had the opposite effect. The usage of SMC regenerant helped to reduce non-recoverable creep compliance by adjusting the proportion of viscoelastic-plastic components in recycled asphalt. Furthermore, the stiffness modulus results indicated that the addition of SMC regenerant improved the recovery performance of recycled asphalt at a low temperature. The recommended contents of SMC regenerant and SBS-modified asphalt are 7.88% and 150%, respectively, with a shear temperature of 157.7 & DEG;C.

Automated summary

This study investigates the impact of material design parameters on the physical and mechanical properties of recycled asphalt. A Box-Behnken design is utilized to determine the optimal preparation scheme for 17 groups of recycled asphalt. The effects of SMC regenerant content, SBS-modified asphalt content, and shear temperature on the mechanical properties of recycled asphalt are analyzed, and the optimal processing parameters are determined by a response surface model.