Effect of Kaolin on Asphalt Concrete Properties Under Aging Conditions

Asphalt modification is an essential process in enhancing the performance and durability of asphalt mixtures. Recently, many research has been carried out in order to shift construction industry into a green and sustainable industry. This study investigates the effect of kaolin as a partial replacement for asphalt in asphalt concrete, focusing on its impact on the mechanical properties of the mixture under various aging conditions. The asphalt mixtures were subjected to Marshall stability, resilient modulus, and dynamic creep tests to assess stability, stiffness, and rutting resistance. The results show that the incorporation of kaolin improves the overall performance of the asphalt mixtures, with 6% kaolin replacement providing the most favorable balance between stability, stiffness, and flexibility. Unaged samples with higher kaolin content exhibited increased Marshall stability, resilient modulus, and dynamic creep modulus, indicating enhanced rutting resistance. Long-term aging further enhanced the mechanical properties, with kaolin-modified mixtures showing better performance compared to their short-term aged counterparts. These findings suggest that kaolin can be an effective modifier in asphalt mixtures, offering a sustainable and cost-effective solution to improve the durability and performance of pavement materials.