Adopting Viscosity Grading System for Proper Selection of Paving Asphalt in Sudan

Selection of proper asphalt binder is one of the most important factors considered in asphalt mixture design. This paper is aimed to -overview the important role of adopting the viscosity grading system in performance and durability of flexible pavements in Sudan. The -literature of the traditional grading systems with their respective advantages and disadvantages is intensively reviewed. An effort is made -to verify the viscosity grading system is more realistic, reliable and practical than the old penetration grade. Twenty samples of asphalt -cement, selected from penetration grades 60/70 and 85/100, were subjected to laboratory testing for measuring their consistency and -safety properties. The results revealed that asphalt binders, from different sources used in the industry are highly temperature susceptible, -though they have complied with the standards. Recommendations have been made to implement the viscosity grading system in order to -improve the quality, performance and durability of bituminous pavements in Sudan. -