Utilizing Network and Project-Level Data to Evaluate Impact of Reclaimed Asphalt Pavement and Recycled Asphalt Shingles on Laboratory and Field Performance in Texas

The incorporation of reclaimed asphalt pavement (RAP) and recycled asphalt shingles (RAS) in asphalt mixes is encouraged as long as the modified mix exhibits equal or improved performance. Through the integration and data mining from several statewide databases, and extensive laboratory and field testing, this paper investigates the performance of asphalt mixes containing RAP, RAS, or both relative to similar mixes with virgin components. The integration of several databases permitted a network-level investigation of performance patterns. The reasonableness of the observed performance patterns was assessed using the results from the Hamburg wheel tracking tests (HWTT) and indirect tensile strength tests performed on specimens from several sites included in a network-level database. Furthermore, the retrieved network-level data were cross-referenced to the results from a historical performance database. At project level, HWTT and the overlay tester tests were performed on samples from several dozen sites to characterize laboratory performance. Field performance of these sites was also documented through periodic cracking and rutting surveys. From the network-level assessment, the impact of RAP, RAS, or both on the performance of the mixes was found to be mix-dependent. The combination of RAP and RAS seems to negatively affect cracking resistance. Further, dense-graded and Superpave mixes with RAP, RAS, or both exhibit higher cracking potential with minimal impact on rutting resistance. The project-level field performance evaluation shows that fatigue cracking propagates at a higher rate for sections with RAP and RAS than for sections with only RAP.