Validation of Gyratory Mix Design in Iowa, TR-667, 2016

(2016) Validation of Gyratory Mix Design in Iowa, TR-667, 2016. Transportation, Department of


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The design number of gyrations (Ndesign) introduced by the Strategic Highway Research Program (SHRP) and used in the Superior Performing Asphalt Pavement (Superpave) mix design method has been commonly used in flexible pavement design throughout the US since 1996. Ndesign, also known as the compaction effort, is used to simulate field compaction during construction and has been reported to produce air voids that are unable to reach ultimate pavement density within the initial 2 to 3 years post-construction, potentially having an adverse impact on long-term performance. Other state transportation agencies have conducted studies validating the Ndesign for their specific regions, which resulted in modifications of the gyration effort for the various traffic levels. Validating this relationship for Iowa asphalt mix designs will lead to better correlations between mix design target voids, field voids, and performance. A comprehensive analysis of current Ndesign levels investigated the current levels with existing mixes and pavements and developed initial asphalt mix design recommendations that identify an optimum Ndesign through the use of performance data tests.

Item Type: Departmental Report
Keywords: Asphalt mixture compaction, asphalt mixture design, gyratory compaction, optimum binder content, pavement performance, Superpave mix design
Subjects: Transportation > Pavements
Transportation > Pavements > Asphalt
Transportation > Materials
Transportation > Roads and highways
Transportation > Research
Transportation > Research > Asphalt
Transportation > Design and Construction
ID Code: 22605
Deposited By: Iowa DOT Library
Deposited On: 05 Aug 2016 12:00
Last Modified: 05 Aug 2016 12:00