Suggested Citation:
Rahman, Mohammad, John T. Harvey, Julian Brotschi, David Jones (2024)

Effect of Coarse Reclaimed Asphalt Pavement on the Performance of Rubberized Hot Mix Asphalt: A Binder Level Study

There is growing interest in adding some reclaimed asphalt pavement (RAP) to rubberized hot mix asphalt (RHMA). However, the binder from RAP is expected to reduce the need for recycled tire rubber. Therefore, the coarse RAP can be utilized as an aggregate replacement with minimal binder replacement. Based on industry feedback, 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.