Mahyar Arabani, Janat Farkhondeh
The asphalt industry is increasingly urged to adopt sustainable practices by utilizing bio-based and recycled resources. This study evaluates the performance of warm mix asphalt (WMA) modified with chitosan derived from shrimp shell waste (SSPCH). Chemical characterization of modified bitumen was conducted using SEM and FTIR, while mechanical performance was assessed through Marshall stability, repeated load axial, indirect tensile strength (ITS), and semi-circular bending tests. Results identified an optimal SSPCH content of 6%. This modification significantly enhanced rutting resistance, reducing permanent strain by 38% compared to the control. The modified mixtures also met ASTM D4867 requirements, showing a 24.5% increase in ITS and a 23% improvement in Tensile Strength Ratio (TSR), indicating superior moisture damage resistance. The enhancement is attributed to SSPCH's physicochemical properties, which promote a stronger bitumen-aggregate bond. This research confirms SSPCH as a viable bio-additive for developing more durable and sustainable asphalt pavements.