Performance evaluation of rapeseed oil-based derivatives modified hard asphalt binders: Towards greener and more sustainable asphalt additives

Hard asphalt binder is regarded as a favorable option in comparison to polymer-modified asphalt for rutting due to the benefits of cost-effectiveness and extreme stiffness behavior. However, its inherent poor ability to withstand fatigue damage and thermal cracking restricts its applications as a pavement material. This study aimed at enhancing the low-temperature and fatigue performance of hard asphalt binders with newly-developed rapeseed oil (RO)-based derivatives. Two rapeseed oil-based derivatives of epoxidized rapeseed oil (ERO) and acrylated epoxidized rapeseed oil (AERO) were laboratory synthesized through oxidation and ring-opening grafting reactions, respectively. Fourier transform infrared spectroscopy (FTIR) and Hydrogen nuclear magnetic resonance (1were conducted to confirm the successful synthesis of derivatives. Mass loss, aging index, performance grading, temperature-frequency sweep, linear amplitude sweep and bending beam rheometer test were employed to assess the modified effects of rapeseed oil-based derivatives on two types of hard asphalt binders. To further explore the differences between RO and derivatives, the properties of modified hard asphalt binders using two derivatives were compared against the performance of RO-modified hard asphalt binders. With the additional RO, ERO, and AERO, the modified hard asphalt binders had significantly improved the resistance to thermal cracking and fatigue damage at low and intermediate temperatures, respectively. RO was found to have the most positive effect on the stress relaxation and the most adverse effect on the stiffness of hard asphalt binders. While, ERO-and AERO-modified hard asphalt binders had shown better antioxidative and anti-aging performance than that of RO-modified hard asphalt binders. Additionally, AERO-modified hard asphalt binders were noticed to have improved the elasticity of hard asphalt binders owing to the formation of a polymer elastic network. According to the study, two rapeseed oil-based derivatives had shown great potential as green and sustainable asphalt modifiers on the improvement of thermal and fatigue cracking resistance with the minimal adverse effect on anti-rutting performance of the hard asphalt binders. The test results revealed that the rapeseed oil-based derivatives modified hard asphalt binders could be employed in various pavement applications with great economic and sustainable benefits.