01660866

Component

In order to fully evaluate the effects of reclaimed asphalt pavements (RAP) in hot mix asphalt (HMA) mixes, the level of blending between the RAP and virgin binders needs to be determined. Asphalt mixtures are designed with the assumption that full blending between RAP and virgin binders is attained. However, the actual percentage of binder blending is unknown. It is critical to quantify the level of blending between virgin and RAP binders to be able to develop strategies to improve the performance of high RAP mixtures. Since the binder of asphalt mixtures with RAP is a combination of both the virgin binder and the binder from the RAP material, increasing the total RAP percentage of the asphalt mixture will increase the amount of the aged RAP binder in the final mixture and reduce the ductility of the final product. However, in addition to the increased stiffness effect, lower blending percentages can also reduce the total binder content of the asphalt mixture and reduce cracking resistance. In this study, blending of RAP and virgin asphalt binders is quantified using binder extraction and recovery and semi-circular bend (SCB) testing. The impacts of mixing temperatures, RAP gradation, RAP source on blending was also determined. Recommendations were also provided to consider blending in asphalt mixture design.

This paper was sponsored by TRB committee AFK30 Standing Committee on Non-Binder Components of Asphalt Mixtures.

18-01228

English

6p

2018

Transportation Research Board 97th Annual Meeting

Digital/other

References; Tables

Bituminous binders; Blending; Mix design; Reclaimed asphalt pavements; Recommendations

Design; Highways; Materials; Pavements

Transportation Research Board Annual Meeting 2018 Paper #18-01228

TRIS, TRB, ATRI

Jan 8 2018 10:18AM