Assessing the Impact of Varying Fines and Antistripping Agent on Moisture Susceptibility in Asphalt Concrete Mixtures

Sustainable infrastructural development is vital for both developed and developing countries. The primary concern in hot mix asphalt (HMA) pavements is related to damages caused by moisture. This research makes efforts to evaluate the moisture susceptibility of a dense-graded surface HMA mixture using simple performance tests (SPTs) and Superpave indirect tensile tests (IDTs). Coating of fines (dust) on the aggregate can prevent the asphalt binder from bonding directly to the surface of the aggregate. Therefore, SPT and IDT have been performed by varying the proportion of fines (3%, 6%, and 9%) in the mix. For each proportion of fines, the optimum asphalt content was determined and used for further preparation of test specimens. The addition of hydrated lime [Ca(OH)2] to asphalt mixtures improved the adhesive bond between aggregate and bitumen, as well as reduced the occurrence of stripping. In addition, when aggregates coated with clays, hydrated lime with a pozzolanic ally to remove those deleterious materials. The amount of antistripping agent incorporated was 1.5% by weight of dry aggregate, a proportion commonly used in the industry for such applications. Standard Marshall Mix design procedure was employed to design the asphalt mixtures. The laboratory investigation and subsequent statistical analysis were conducted using Minitab-15 software, which yielded significant insights into the effectiveness of hydrated lime as an antistripping additive in asphalt concrete mixtures. The findings indicate that incorporating hydrated lime substantially facilitates mitigating moisture-induced stripping in asphalt mixtures.