Enhancing Road Recycling Technology: Preparation, Testing, and Application of Recycled Semi-Flexible Pavement Materials with Reclaimed Asphalt Pavement Resources

Abstract

To enhance the performance of recycled pavement materials and diversify the recycling methods for reclaimed asphalt pavement, a preparation method for recycled semi-flexible pavement (RSFP) materials was proposed. This study investigated the high-temperature performance, low-temperature performance, water stability, secondary aging resistance, fatigue performance, and engineering applications of RSFP materials. Experimental results demonstrate that RSFP materials exhibit superior high-temperature stability and secondary aging resistance compared to conventional recycled pavement materials. The performance of RSFP materials is directly influenced by the air voids within the asphalt mixture skeleton and the filling rate of the cementitious grouting material. A more complete and thicker internal cement skeleton formed by the cementitious grouting material enhances high-temperature stability, whereas a more incomplete and slender internal cement structure improves low-temperature crack resistance. As the filling rate decreases, the cement skeleton within the RSFP materials becomes increasingly discontinuous and incomplete, leading to a gradual reduction in fatigue life. Notably, the fatigue life of RSFP materials reaches its optimum at an air void content of 25%. Finally, the application of RSFP materials in road engineering was validated through two years of detection and observation on the experimental road, supporting its applicability under heavy traffic conditions. These findings not only advance sustainable practices in road construction but also provide a valuable solution for effectively utilizing reclaimed asphalt pavement in high-traffic infrastructure projects.

Keywords: Reclaimed asphalt pavement, Semi-flexible pavement materials, preparation, pavement performance, Engineering applications