Rejuvenation of Asphalt Subjected to Thermally Accelerated Aging with an Asphalt-Miscible Self-Assembling Starch-Based Fatty Acid Ester

Asphalt rejuvenation technologies are utilized in road paving and roofing and play a vital role in advancing sustainable infrastructure development. Given that conventional asphalt rejuvenators are derived from petroleum, considerable attention has been drawn to the development of eco-friendly and renewable bioderived alternatives. We herein investigated the asphalt-rejuvenating effect of 2,3,4,6-O- tetrapalmitoyl-1,5-anhydro-d-glucitol (C16AG). The evaluation was conducted using penetrability and viscoelasticity (complex modulus) measurements, composition analysis, and atomic force microscopy. The addition of C16AG to asphalt thermally aged at 80 °C for 180 days increased its penetrability from 6 to 18 (1/10 mm), reduced the complex modulus (|G*|) at 25 °C from 6.7 × 106 Pa to 1.2 × 106 Pa, decreased the asphaltene content from 38 to 20%, and eliminated the bee structures, indicating resin and asphaltene aggregation. Unlike conventional bio-rejuvenators, such as vegetable oils or waste pig fat, C16AG not only self-assembles into fibrous structures within asphalt but also demonstrates a markedly higher effect to reduce asphaltene and resin aggregation. We ascribe these rejuvenating effects to changes in the asphalt colloid microstructure due to the self-assembly of C16AG into fibers after mixing with the resins and asphaltenes in aged asphalt.