A novel aging acceleration rate equation for accelerated weather aging test of high viscosity modified asphalt: Theoretical derivation and experimental correction

Abstract

Accelerated weather aging test is a novel aging method for evaluating the long-term real aging behavior of large-void asphalt pavement (OGFC) and high viscosity modified asphalt (HVMA). However, uncertainties in aging acceleration rate and inconsistencies in selecting weather parameters are the core issues restricting its widespread application. To address these issues, this study proposes a novel approach to construct aging acceleration rate equation for the accelerated weather aging test, considering aging kinetics theory and experimental data correction. First, three representative weather aging combinations were chosen, and a theoretical model for aging acceleration rate was preliminarily constructed based on thermal aging kinetics theory, photoaging kinetics theory, and humidity peak model. Then, by comparing the aging performance between accelerated weather aged HVMA and natural aged HVMA, the experimental aging acceleration rate range (AF1) was determined, and the theoretical model was parameterized to formulate the aging acceleration rate equation at the binder level. Finally, based on the aging performance comparison between accelerated weather aged HVMA and recycled HVMA from field-aged OGFC, the experimental aging acceleration rate range (AF2) was determined, and the mixture-level aging acceleration rate equation after parameter correction was determined. The results show that after theoretical derivation and experimental correction, the aging acceleration rate equation at the binder level incorporates temperature acceleration rate, solar radiation acceleration rate, humidity acceleration rate, and binder correction coefficient Cα (Cα = 1.214). For the mixture level, it also requires considering mixture correction coefficient Cβ (Cβ = 3.731). Under the three typical weather aging combinations in this study, a one-day accelerated weather aging test can simulate the aging effect of 18, 40 and 81-days natural aging for HVMA or 2, 5, and 10-months field aging for OGFC. The aging acceleration rate equations involve real weather parameters, allowing the determination of aging acceleration rates under any combination of weather parameters. This provides a foundation for weather parameter selection and enables accurate simulation of long-term aging of HVMA and OGFC in the laboratory.