Laboratory Evaluation of Biobased Epoxy Asphalt Binder for Asphalt Pavement

Abstract

In recent years, concerns about the depletion of nonrenewable resources, infrastructure sustainability, and environmental impact in pavement engineering have led to substituting petroleum-based paving materials with their biobased counterparts. Research efforts have been attempted to produce asphalt from renewable bioresources. As a special modifier for asphalt, petroleum-based epoxy resin has been used in a few asphalt paving projects that require superior performance of asphalt mixtures. This paper presents an attempt to develop a biobased epoxy modifier for asphalt using an epoxidized soybean oil (ESO) and a biobased curing agent, maleic anhydride (MA). The proper proportions of ESO, MA, and a base asphalt were determined to achieve a homogenous biobased epoxy asphalt binder (BEAB) with the desired properties evaluated by a rotational viscosity test, a penetration test, and a dynamic shear rheometer test. Pavement performance–related properties of asphalt mixtures using such a BEAB were also preliminarily evaluated using a Marshall stability test. At an optimum ratio of .45∶1∶8 for MA∶ESO∶asphalt, the BEAB showed higher Marshall stability than a mixture containing the base asphalt. Further research, however, is still needed to evaluate the asphalt mixtures with more pavement performance–based tests and to refine the BEAB formula.