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Title:Hma Dynamic Modulus Predictive Models (a Review)
Author(s):Garcia, Gabriel; Thompson, Marshall
Subject(s):HMA modulus, hot mix asphalt, HMA modulus predictive models
Abstract:The most important hot-mix asphalt (HMA) property influencing the structural response of a flexible pavement is the HMA modulus (EHMA). Dynamic modulus concepts are reviewed. The construction of master curves for HMA mixtures is presented. The procedures are based on the fitting of a sigmoidal function. Two IE*I predictive equations are presented. The Witczak, as proposed in the new AASHTO 2002 Design Guide, and the Hirsch model. In general, both appear to be in good agreement and have similar accuracy. The Witczak predictive equation requires eight input parameters. This information is normally available from material specifications or volumetric design of the mixture. The master curve for IE*I can be developed directly by using the binder A and VTS parameters in the viscosity components of the equation. The Hirsch model needs only three input parameters, which are available from the routine Superpave mix design process. To build the IE*I master curve, a master curve for IG*Ibinder has to be developed to take into account the effect of temperature and frequency. This can be done with data obtained from Dynamic Shear Rheometer tests. Several studies are presented where the dynamic modulus predictive models are evaluated. The studies used different binders and represent typical mixtures used by different agencies. The results clearly confirm the good agreement and similar accuracy between the Witczak equation and the Hirsch model and between these models and dynamic modulus obtained from laboratory tests. In general, it is concluded that both predictive models generate sufficiently accurate and reasonable dynamic modulus estimates adequate for use in mechanistic-empirical design, at least for broad range of binders and mixtures studied.
Issue Date:2007-01
Genre:Technical Report
Publication Status:published or submitted for publication
Peer Reviewed:not peer reviewed
Sponsor:Illinois Department of Transportation ICT-R39
Rights Information:No restrictions. This document is available to the public through the National Technical Information Service, Springfield, Virginia 22161
Date Available in IDEALS:2013-11-14

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