Impact of recycled asphalt pavement material variability on pavement performance

Abstract

In recent years, recycled or reclaimed asphalt pavement (RAP) has been used increasingly due to its advantages in building sustainable pavement infrastructure. In the meantime, concerns have been raised regarding the performance of mixtures involving RAP. One of the major concerns comes from the material variability because it is believed to possibly result in poor pavement performance, particularly for mixtures with high RAP content. To address this issue, this study is conducted along two steps hierarchically. First, RAP samples were collected from four field stockpiles. RAP material variability was established based on laboratory testing. Second, a factorial design was carried out for designing mixtures with varying RAP contents ranging from low (10%) and medium (25%) to high (40%). In particular, different blending conditions between RAP and virgin binders, including zero, partial, and full blending, were considered. The Mechanistic–Empirical Pavement Design Guide was used to predict pavement performance including distresses and ride quality for each design scenario. The relationships (1) between the RAP content and performance variability and (2) among the variabilities of different performances due to RAP material variability are finally revealed.