01661023

Component

This paper describes a study that investigated the potential implications of using reclaimed rubberized asphalt pavement (R-RAP) materials as partial binder and aggregate replacement in new conventional dense-graded asphalt concrete mixes. The use of rubberized hot mix asphalt (RHMA) in pavements in California has been increasing since the early 1990s. As these RHMA layers reach the end of their design lives they are being milled off and replaced with HMA or new RHMA. The millings are being added to RAP stockpiles, which in turn are reused in new conventional HMA. There is no published information documenting whether the use of R-RAP influences mix performance. Laboratory test results indicate that adding R-RAP to dense-graded HMA could potentially yield some improvement in overall rutting performance, but it could also have a potentially overall negative effect on fatigue and low-temperature cracking performance. The degree of change in rutting and cracking resistance in the HMA mixes was dependent on the R-RAP source, with mixes containing millings only from RHMA layers performing slightly better than mixes containing both R-RAP and RAP, and only RAP. Based on these findings, there appears to be no reason or justification for separating R-RAP and RAP millings or maintaining separate stockpiles at asphalt plants.

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

18-01511

English

4p

2018

Transportation Research Board 97th Annual Meeting

Digital/other

References

Asphalt concrete pavements; Asphalt rubber; Hot mix asphalt; Laboratory tests; Pavement performance; Reclaimed asphalt pavements

Asphalt millings

California

Highways; Materials; Pavements

Transportation Research Board Annual Meeting 2018 Paper #18-01511

TRIS, TRB, ATRI

Jan 8 2018 10:23AM