Performance evaluation of asphalt mixtures containing high-RAP binder content and bio-oil rejuvenator

TLDR

The study evaluated asphalt mixtures with date seed oil–modified binders and RAP content ranging from 20 % to 40 %. Moisture susceptibility, rutting, stiffness, and fatigue were measured with standard tests, and regression models were developed to predict fatigue life. DSO had only a minor effect on moisture susceptibility, worsened rutting, but increased fatigue life by up to 15 % at 20 % RAP; however, mixtures with 40 % RAP require other solutions.

Abstract

The objective of this study was to conduct a laboratory-based research study that evaluated the performance of asphalt mixtures prepared with date seed oil (DSO) modified binders containing different amounts of Reclaimed Asphalt Pavement (RAP) binder varying from 20 to 40%. To this end, moisture susceptibility, rutting performance, stiffness modulus and fatigue resistance of the mixtures were assessed using Modified Lottman (AASHTO T283), Wheel Tracking Test (WTT), Indirect Tensile Stiffness Modulus (ITSM) and four-point beam fatigue, respectively. Regression models were provided to estimate fatigue life of the mixes. The results showed that moisture susceptibility of the mixes was slightly influenced by DSO content. Rutting performance of the mixes was deteriorated, while the addition of DSO improved fatigue life of the specimens containing 20% RAP up to 15%. However, in order to employ 40% or more of RAP binder, other alternatives should be considered.