Assessing the efficacy of alginate-encapsulated rejuvenators from soybean oil sludge and fatty acid for enhanced self-healing capacity of asphalt mixtures

Abstract

The effectiveness of incorporating fatty acid (SSFA) and soybean oil sludge (SS) as rejuvenating agents, encapsulated via ionotropic gelation of alginate with calcium, was investigated in this study. Four variations of capsules were produced: C/SS0.1, C/SS0.2, C/SSFA0.1, and C/SSFA0.2, with rejuvenator/water ratios ranging from 0.1 to 0.2. These capsules were then introduced at 0.6% of the total weight into the mixture. Initial assessments focused on capsule properties and their incorporation into mixtures. Impact evaluations included void volume, tensile strength, moisture damage, stiffness, rutting, and fatigue life. The capsules exhibited resistance and uniformity, impacting void volume and enhancing resilient modulus, fatigue life, and moisture resistance. The self-healing potential was evaluated through dynamic loading using the Semicircular Bending Test and a 24-hour resting period. The capsules significantly enhanced self-healing levels, recording values of 169%, 72%, 109%, and 90% for C/SS0.1, C/SS0.2, C/SSFA0.1, and C/SSFA0.2 mixtures, respectively, compared to 62% for capsules-free mixtures.