Informations et ressources scientifiques
sur le développement des zones arides et semi-arides

Titre : Comprehensive Evaluation of Asphalt Mixtures in Arid Climatic conditions

Auteur : Singh, Aditya

Université de soutenance  : University of Nevada Reno

Grade : Master of Science in Civil and Environmental Engineering 2022

Résumé partiel
Raveling is the leading cause of poor performance in the asphalt-wearing course in Kuwait’s arid climatic conditions. The extreme conditions of Kuwait and poor asphalt mix design characteristics have further accelerated the raveling and deterioration of the in-service asphalt pavements. Combating this issue requires sophisticated asphalt mixture designing. Therefore, very recently, Kuwait has adopted the Qatari Superpave mix design procedure to improve the current condition of the asphalt pavement performance. In this study, a comprehensive evaluation of the existing Superpave mix design was undertaken, and the recommended modifications for the mix design were made to address raveling concerns in Kuwait.To carry out this study, local materials were collected from Kuwait, and their physical properties were evaluated to ensure their conformity with the latest specifications. After this, two mix designs, i.e., the traditional Marshall mix design practiced in Kuwait and the newly adopted Superpave mix design, were prepared as per the Qatari specifications. The performance of the finalized mix designs was evaluated through the indirect tensile strength ratio (TSR), Hamburg wheel-track test (HWTT), dynamic modulus (|E*| referred to as E*), cyclic fatigue (CF), and stress sweep rutting (SSR), at unconditioned (UC) and moisture-conditioned states at one freeze-thaw cycle (1-C) and three freeze-thaw cycles (3-C). The TSR, HWTT, and E* were performed for both the asphalt mix designs. However, the CF and SSR tests were only performed for the Superpave mix design based on the findings from TSR, HWTT and E* test at multiple freeze-thaw cycles and limitations in the material quantities. HWTT results showed that both asphalt mixtures (Marshall and Superpave) exhibited excellent resistance to moisture damage and rutting. TSR test results showed that the Marshall asphalt mixture had higher dry and wet indirect tensile strength (TS) than the Superpave asphalt mixture. However, the TSR values were higher for the Superpave asphalt mixture, indicating that the Marshall asphalt mixture was more susceptible to moisture damage. Similar observations were made for the E* test results, where the Marshall asphalt mixture showed higher stiffness initially than the Superpave asphalt mixture but lower moisture damage resistance than the Superpave asphalt mixture. Overall, HWT, TSR, and E* results showed that the newly adopted Superpave asphalt mixture was successful and proven to improve the moisture damage resistance of the mix compared to the Marshall asphalt mixture.To study the long-term resistance of the Superpave asphalt mixture to raveling, the CF and SSR results were used to assess the properties after multiple freeze-thaw cycles and to predict the asphalt pavement performance using mechanistic analysis

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