Abstract for presentation (Poster or Podium) with a Paper in the Conference Proceedings
Highway Pavements
.jpg "Mohammad Ashiqur Rahman, MS (he/him/his) photo")
Mohammad Ashiqur Rahman, MS (he/him/his)
Graduate Student Researcher
University of California Davis
Davis, CA, United States
Mohammad Ashiqur Rahman, MS (he/him/his)
Graduate Student Researcher
University of California Davis
Davis, CA, United States
John T. Harvey, n/a
Professor
University of California Davis
Davis, California, United States
Julian Brotschi, n/a
R&D Engineer II
University of California Davis
Davis, California, United States
David Jones, Ph.D.
Professional Research Engineer
University of California, Davis
Davis, California, United States
Mohammad Ashiqur Rahman, MS (he/him/his)
Graduate Student Researcher
University of California Davis
Davis, CA, United States
There is growing interest in adding some reclaimed asphalt pavement (RAP) to rubberized hot mix asphalt (RHMA). However, if binder replacement is the goal, then the amount of recycled tire rubber used will be reduced. Therefore, the coarse RAP can be utilized as an aggregate replacement with minimal binder replacement. Based on industry feedback prior to this study, it was estimated that the additional binder mobilized and blended from coarse RAP in plant-produced mixes is between 0.2% and 0.5% by the total mass of mix. According to that, binder blends were prepared in the laboratory by adding aged binder from coarse RAP to rubberized binder to evaluate the effect of RAP binder on the performance of RHMA. It was found from this study that the addition of RAP to the binder somewhat negatively affects the low-temperature grade and appears to make it less able to relax thermal contraction stresses at cold temperatures. The addition of RAP increases the amount of elastic recovery of the mix, which is expected to increase rutting resistance. The intermediate-temperature grade does not appear as sensitive to increases in a small percentage of RAP binder as the high- and low-temperature grades. Increasing aging products in the binder, measured by carbonyl content, were observed as increasing amounts of RAP were added and as blended binder aging was increased. The carbonyl contents of the RAP sources were much higher than those of even the PAV-aged control binder.