Effect of Short and Long Term Aging on Moisture Susceptibility of SMA Mixtures Stabilized with Waste Jute Fibers

Stone Matrix Asphalt (SMA) is a hot, gap-graded asphalt mixture known for its outstanding durability and resistance to rutting. It relies on stabilizing agents to prevent the binder drainage caused by its stone-on-stone contact. This research investigates the effect of incorporating Waste Jute Fiber (WJF) on the moisture susceptibility of SMA mixtures under three aging conditions: unaged, Short-Term (ST), and Long-Term (LT). Three WJF lengths (5, 10, and 15 mm) were used at four concentrations (0.1%, 0.3%, 0.5%, and 0.7%) by total mixture weight. The Marshall test was utilized to evaluate volumetric and mechanical properties, while the drain-down test assessed binder drainage. Indirect Tensile Strength (ITS) and compressive strength tests were conducted to evaluate the moisture susceptibility after aging. The results showed that all WJF contents and lengths yielded a higher Tensile Strength Ratio (TSR) and Index of Retained Strength (IRS) values compared to the control mixtures. Moreover, ITS and compressive strength increased with aging due to binder hardening. The TSR and IRS values of the aged samples indicate that increasing the WJF content up to an optimal level significantly reduces the susceptibility to moisture and oxidative aging. The mixture with 0.5% WJF at 10 mm length exhibited the greatest improvements, with TSR increases of 14.12%, 16.69%, and 19.39%, and IRS increases of 18.95%, 21.77%, and 26.44% for unaged, ST, and LT aging, respectively.