Date of Award


Document Type


First Advisor

Fini, Elham H.


This study was undertaken to investigate the effects of amine-based modifiers on the rheological characteristics of particle-filled viscous media such as recycled asphalt shingles (RAS). RAS are a recycled material that contains high concentrations of asphalt which has the potential for use in hot mix asphalt (HMA) when added to virgin asphalt. When using the RAS as a binder in HMA it is important to mix it with the virgin asphalt properly to achieve the best performance, which can also be enhanced by the incorporation of amine-based modifiers. Tear-off shingles were acquired from a roofing company and ground very fine so that 85% of the particles passed through sieve number 200. The virgin asphalt binder (PG 64-22) and three (20%, 30%, & 40%) percentages of grounded RAS were blended at a temperature of 180°C at a rotational speed of 400 rpm. These three mixtures were then blended with three different amine-based modifiers (1.5% of Rediset®, 0.5% of Evotherm®, and 5% of bio-binder by weight of mixture) at 135oC and a rotational speed of 400 rpm. The percentage of each modifier was selected based on recommendations of the manufacturers. The properties of the blended binder were studied using a rotational viscometer (RV) utilizing a Brookfield Viscometer DVIII-Ultra. Two different spindles were used to measure the viscosity of the binders at four different temperatures (105oC, 120oC, 135oC, and 150oC) and six (5, 10, 20, 25, 50, and 100) different rotational speeds. The analysis showed that viscosity increased with increasing percentages of RAS; however, the viscosities decreased after incorporation of the amine-based modifiers.