Reliability-Based Recycling of Reclaimed Asphalt Pavement Using a t-Distribution Guarantee Rate Method and a Ternary...

Area of Science:

• Materials Science
• Civil Engineering
• Sustainable Construction

Background:

• Large-scale reclaimed asphalt pavement (RAP) utilization is hindered by aged asphalt (AA) variability and incomplete rejuvenation understanding.
• Addressing gradation variability and optimizing AA recovery are crucial for sustainable road infrastructure.

Purpose of the Study:

• To improve aged asphalt (AA) recovery and performance in reclaimed asphalt pavement (RAP) through composite rejuvenation.
• To develop a reliable method for reclaimed material selection and mix design considering gradation variability.

Main Methods:

• Developed a t-distribution model for gradation variability and a reliability-based selection method.
• Formulated a ternary composite rejuvenation system with Rejuvenator 1 (R1), SBS-modified asphalt, and base asphalt (BA).
• Assessed AA performance using physical, rheological, and micro-analyses (FTIR, fluorescence microscopy, GPC).

Main Results:

• The t-distribution guarantee rate method effectively quantified RAP gradation fluctuations, ensuring stable sources at a 90% guarantee rate.
• 10% R1 restored high-temperature performance; 30% SBS-modified asphalt and BA enhanced low-temperature crack resistance.
• Micro-analyses confirmed rejuvenation via physical blending, dilution, and molecular-weight distribution optimization, without new functional groups.

Conclusions:

• A reliable method for RAP source evaluation and mix design was established using a t-distribution model.
• The developed composite rejuvenation system effectively restores aged asphalt performance.
• The study provides a scientific basis for the enhanced utilization of reclaimed asphalt pavement.