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Abstract
Bituminous pavements were first constructed in the United States during the late 1800’s. Since this time several mixture design methods have been developed to improve the quality of asphalt concrete mixtures. These include methods such as Hveem, Marshall and Superpave (Roberts, 1996). The Marshall method was developed during the 1930’s and has undergone several refinements over the years. The Superpave method was developed during the Strategic Highway Research Program in the late 1980’s. The Marshall mix design procedure for the majority of its pavement designs. However, the Superpave method is used for the high traffic volume roads. Superpave is an acronym for Superior Performing Asphalt Pavements. It is the product of the Strategic Highway Research Program. Superpave includes a new mixture design and analysis system based on erformance characteristics of the pavement. It is a multi- faceted system with a tiered approach to designing asphalt mixtures based on desired performance. There is a great deal of work underway to refine and validate the existing Superpave requirements. The National Cooperative Research Program, Federal High Administration, and the State Departments of Transportation are all working on filling the gaps and improving the way we specify, design and build our asphalt pavements. Superpave is only the beginning not the end of our road to true performance based design and construction specifications. Superpave has put us well ahead on that road, but there will always be things to improve on.
One of the primary differences between the Marshall and Superpave methods is the aggregate specifications. The stability of asphalt concrete is strongly dependent on friction between the aggregate particles. The Marshall method controls the stability of the asphalt concrete by testing the asphalt concrete. The Superpave method uses tests and specifications on the aggregates to assure interparticle friction. It will be concluded that Marshall method is enough to determine the properties of asphalt concrete mixture than the Superpave method. Superpave method is more expensive than Marshall method.