ABSTRACT
ABSTRACT: Reclaimed Asphalt Pavement (RAP) is a useful alternative to virgin aggregates in Hot-Mix Asphalt (HMA) as it reduces cost, conserves energy and enables reuse of existing asphalt pavement. However, use of higher percentage of RAP sometimes leads to drier mixes that are often susceptible to early cracking. In this study, cracking resistance of Superpave mixtures with varying asphalt and RAP contents were investigated. HMA specimens were prepared based on Superpave mix design criteria for 12.5-mm (1/2-inch) nominal maximum aggregate size. Specimens were compacted using the Superpave gyratory compactor. Repeated load Semi-Circular Bending (SCB) tests and Texas Overlay Tests (OT) (TEX-248-F) were performed to evaluate cracking resistance of Superpave mixtures containing three asphalt contents (5.2%, 4.9%, and 4.6%) and three RAP percentages (20%, 30%, and 40%) from two distinct sources. Results from both crack tests showed that, with the decrease in asphalt content, cracking propensity increases. Thus conclusions regarding proper RAP percentage use were drawn depending upon the binder content and grade of the RAP source.
