Evaluation of High RAP Mixture Production, Construction, and Properties

摘要

In 2007, the Virginia Department of Transportation (VDOT) introduced specifications to allow reclaimed asphalt pavement (RAP) percentages of up to 30% in asphalt surface mixtures without a change in the virgin binder grade. Since 2007, increasing material costs and a growing awareness of the quantity of RAP available for use have sparked interest in asphalt mixtures having a higher percentage of RAP. Recently, VDOT began to consider the feasibility of allowing the use of surface mixtures with RAP contents of up to 45%, and in June 2013, a trial was constructed containing mixtures with 20%, 30%, 40%, and 45% RAP for evaluation. This paper presents the initial construction and laboratory data (including volumetric, modulus, and flow number results) and discusses the lessons learned from this experience. In general, mixtures containing up to 45% RAP can be successfully designed, produced, and constructed if proper procedures are followed and attention to detail is paid during design, production, and construction. In addition, dynamic modulus and flow number test results indicated no significant difference in performance should be expected among the mixtures evaluated, despite slight differences in volumetric properties.