|Description||Based on the field performance ofseveral Superpave mixtures throughout the state ofNevada during the 1990's, NDOT decided to modify the Superpave volumetric mix design method and construct two test sections side-by-side with the conventional NDOT Hveem mixtures. The modifications of the Superpave volumetric mix design included: a) eliminate the restricted zone requirement on aggregate gradation, b) include a minimum requirement on Hveem stability, c) verify potential performance in rutting with the AP A, and d) include a minimum dry tensile strength of65 psi and a retained tensile strength ratio of70%.
Using the modified Superpave volumetric mix design, NDOT constructed three test sections: two on I-80 in the northern part ofthe state in 2001 and 2003 and one on I-15 in the southern part ofthe state in 2002. Each test section was built as part ofa Hveem designed project which will allow for the direct comparison ofthe performance of mixtures designed with the modified Superpave and NDOT Hveem methods.
This report summarizes the mix designs data and construction activities ofthe Superpave and Hveem sections within each project. Samples were obtained during the construction ofthe test sections.
Additional laboratory testing is currently being conducted on laboratory prepared mixtures and field prepared mixtures to assess the resistance of the mixtures to the failure modes of rutting, low temperature cracking, fatigue, and moisture damage. The construction and post-construction laboratory testing will be coupled with the field performance ofthe test sections to assess the applicability ofthe modified Superpave volumetric mix design method under Nevada's conditions.||