Field performance evaluation of open-graded asphalt friction courses: A survival data analysis

Abstract

Open-graded asphalt friction courses (OGFC) have been used extensively owing to their significant advantages of fast water draining, decreased hydroplaning, increased friction, promoted driving safety, reduced noise levels among others. However, due to their unique material characteristics, pavement engineers have been facing great challenges in effectively maintaining OGFCs under a satisfactory serviceability. This study first summarized the typical maintenance strategies for OGFCs based on the field performance data extracted from the database for the Long-Term Pavement Performance project (LTPP). Then, a series of non-parametric and parametric survival analyses were performed to determine the critical factors to the service life of the OGFCs according to a variety of performance indicators. Prior to the survival analyses, clustering analyses were employed to objectively determine the thresholds for the performance indicators. Results showed that thin overlay, surface treatment, and crack sealing were the most frequently used methods for preserving the OGFCs, while resurfacing alternatives that sealed surface of the OGFCs were rarely used. The OGFCs were considerably more sensitive to the climatic conditions than other factors; sections from the wet, freeze regions showed significantly shorter survival life. The overall service life of the OGFCs was primarily controlled by roughness and skid resistance. Thicker OGFCs were beneficial to the extended survival time in terms of raveling, rutting, and non-wheel path longitudinal cracking.