Assessing bio-oil cutback asphalt for prime coat on semi-rigid base asphalt pavement: Lab experiment & indoor test section application

Abstract

To analyze the potential utilization of bio-oil cutback asphalt (BCA) as an innovative permeable material, this study comprehensively evaluated the road performance of BCA. Infrared spectroscopy and fluorescence microscopy were employed to characterize the components' interaction mechanisms and storage stability within the BCA. The research also involved assessments of interlayer strength, unconfined compressive strength, and dynamic water scouring trials of the base layer. Subsequently, a comprehensive assessment of the road performance of BCA was carried out in conjunction with its application on the indoor test section. The microscopic test results revealed that bio-oil and the penetrant primarily enhanced the asphalt's flow and penetration properties through physical blending. Even after 28 days of storage, no phase separation occurred among the constituents in the BCA. Compared to conventional prime coat materials, the specimens treated with BCA demonstrated notably higher interlayer pull-off and shear strengths at the optimal sprinkling volume. Furthermore, applying BCA to the cement-treated base improved its early strength and erosion resistance. As a result, BCA plays a crucial role in enhancing the structural integrity of asphalt pavements with semi-rigid base layers.