Effect of Introduction of Furfural on Asphalt Binder Aging Characteristics

Asphalt oxidative aging and excessive hardening are known causes of premature pavement cracking. Asphalt aging occurs mainly due to oxidation of certain functional groups and loss of the maltene phase; this in turn causes the asphalt to become stiffer and more brittle. There have been several studies on delaying asphalt oxidation by introducing modifiers and antiaging additives. The present study investigates the effect of the introduction of furfural as an antioxidant. Furfural, an organic compound derived from a variety of agricultural byproducts, has been shown to be a promising modifier for petroleum asphalt binders used in asphalt pavement. The study investigates the effect on asphalt aging characteristics and rheological properties by the introduction of 1%, 2%, or 5% furfural to base asphalt (by weight of the base asphalt). Excessive hardening and brittleness of asphalt caused by oxidation during production and service life increase the susceptibility of asphalt pavements to cracking. Therefore, reducing the susceptibility of asphalt to oxidation could increase pavement service life. In this study, performance characteristics of the base asphalt were compared with those of furfural-modified asphalts using a rotational viscometer, Fourier transform infrared spectroscopy, and a dynamic shear rheometer to evaluate rheological properties of asphalt modified with furfural at different percentages. Each modified asphalt was evaluated in terms of viscosity-temperature susceptibility, shear susceptibility, and oxidative aging resistance characteristics. The study results showed that the addition of furfural helped improve resistance to oxidative aging while enhancing high-temperature performance of asphalt binder. Specifically, it was found that the 2% furfural modification had the lowest aging index, indicating a good effect on reducing the oxidative aging of the binder. Overall, the rheological properties suggest furfural can be a good modifier to improve asphalt binder performance.