Rheological Properties and Microscopic Morphology Evaluation of UHMWPE-Modified Corn Stover Oil Bio-Asphalt

In order to promote the efficient utilization of bio-oil, corn stover oil and petroleum asphalt were used to prepare bio-asphalt. UHMWPE was adopted to strengthen the high-temperature properties of bio-asphalt. UHMWPE-modified corn stover oil asphalt was prepared. Rheological and microscopic tests were carried out to study its performance. The softening point and viscosity of the modified asphalt were enhanced with a rise in the UHMWPE dosage. Its ductility and deformation ability increased at 5 °C. An MSCR test suggested that the asphalt’s creep recovery ability and anti-rutting properties decreased at a high stress level. Meanwhile, the low-temperature rheological behavior of UHMWPE-modified corn stover oil asphalt was superior to that of neat asphalt. The corn stover oil ameliorated the asphalt’s low-temperature properties but weakened its high-temperature behavior. The optimal preparation schemes for UHMWPE-modified corn stover oil asphalt were recommended through a comprehensive analysis of the properties. The recommended dosage of UHMWPE was 3–4%, while the corn stover oil dosage was 5%. However, when the dosage of corn stover oil was 10%, the recommended dosage of UHMWPE was 4%. UHMWPE powder was melted and cross-linked with neat asphalt during high-temperature preparation, demonstrating that UHMWPE can enhance the properties of asphalt. The UHMWPE polymer macromolecules can be dispersed in corn stover oil. UHMWPE can form a compact and robust network structure with asphalt. The feasible application of corn stover oil in road engineering was verified, which provides efficient solutions for waste utilization. This study will contribute to the sustainable development of road construction.