Evolution Analysis of Asphalt Pavement Performance in Its Life Cycle: Case Study in Qinghai-Tibet Highway

Owing to the combination of bitumen aging, traffic loading, and environmental factors, the performance of asphalt will gradually deteriorate with time. However, characterizing the deterioration is still challenging. Aiming to reveal how the performance of asphalt pavement deteriorates with time, the AASHTO design equation was applied to investigate the evolution trend of pavement performance by adopting a reliability method in terms of freeze-thaw cycles. It was found that the combination of the rate of evolution and curvature could identify the abrupt change points and significant variation stages. Risk analysis was introduced to provide a novel method to evaluate the pavement performance evolution by identifying the change of the hazard rate and the cumulative hazard rate. It was found that the evolution curve of asphalt pavement strength reliability could be divided linearly during its life cycle, which can be extended to any n-stage linear deterioration model according to the actual situation. Moreover, reliability levels for pavement strength were also proposed in this research according to the integrated pavement travel and structure performance.