Best Practices for the Design, Evaluation and Quality Control of High Percentage RAP Mixes.

摘要

Placing reclaimed asphalt pavement (RAP) back on the roadway is a common and popular technique in the paving industry. There are always challenges associated with this type of cycling, especially when the RAP content in the newly paved asphalt mix exceeds 20to 30 percent by mass of the total mix. The Federal Highway Administration (FHA) and many state highway agencies have been pursuing usage of high RAP content in asphalt mixes. There are concerns about uniformity of the stockpiled RAP and the brittleness of the RAP aged binder. When using high RAP content in asphalt mixes, high quality can only be achieved through best practices in design, RAP stockpile management, and construction. The Pennsylvania Department of Transportation (PennDOT) has been an advocate of using RAP in asphalt pavements. Under a PennDOT-sponsored project, Penn State was charged with reviewing and revising PennDOT publications based on the most recent research findings in regard to RAP usage. The PennDOT documents that were affected by these practices were Publication 27, Specification 408, and Publication 2 (POM). Most of the changes incorporated into PennDOT publications were applicable to the RAP usage. However, the changes also covered uage of recycled asphalt shingles (RAS). the Overall goal of the work was the adaptation and implementation of accepted best practices for mix design procedures and performance evaluation of higher percentage RAP mixes. the main objective of the work was to make necessary changes to PennDOT publications affected by recently proposed practices by NCHRP 752 and its accompanying report on the best RAP management practices.