Asphalt Binder Performance Grading for the Republic of Yemen Based on Superpave Asphalt Mix-Design

Background: The asphalt binder is considered a temperature-sensitive viscoelastic material. Temperature can cause some common distress of asphalt pavement, such as rutting (permanent deformation), which correlated with high-temperature environments, and thermal cracking, which correlated with low-temperature environments. Objective: This study aimed to establish asphalt binder Performance Grades (PGs) in the Yemeni region to ensure that the asphalt pavement design can effectively resist the distresses of rutting and cracking that occurred due to seasonal temperature changes. Methods: In order to determine the performance grades, the temperature zoning was performed by obtaining the last 10 years temperature data of 19 cities in Yemen gathered by the Yemeni Meteorological Authority. The collected data were analyzed based on the trend and statistical reliability. Three air-pavement temperature prediction models of Superpave, LTPP, and Oman model were used to predict air pavement temperatures. The local performance grades were computed using reliability levels of 50% and 98%. Since the dependent variables of latitude in the Superpave equation can more reflect the geographical locations of Yemeni regions rather than the other models, this study strongly approved the SHARP Superpave model to be used to determine the performance grades. Results: Based on the Superpave model with reliability analyses, performance grade maps were drawn. The most common performance grades recommended in this study for low traffic volume roads were PG64-10, and PG52-10. Conclusion: The findings of this study are highly significant and provide valuable decision support for pavement management and improve the transportation system in the Republic of Yemen.