Validation of a dynamic modulus predictive equation on the basis of spanish asphalt concrete mixtures

• Main Authors: A. Mateos, J. B. Soares
• Format: Article
• Language: English
• Published: Consejo Superior de Investigaciones Científicas 2015-03-01
• Series: Materiales de Construccion
• Subjects: asphalt mixture; asphalt binder; dynamic modulus; mechanistic-empirical design
• Online Access: http://materconstrucc.revistas.csic.es/index.php/materconstrucc/article/view/1683

Dynamic modulus is defined as the ratio of peak cyclic stress to peak cyclic strain under harmonic loading. It is one of the most important properties of asphalt mixtures, since it determines the strain response characteristics as a function of loading rate and temperature. Different simplified models exist that can predict this variable from mixture composition and binder rheological data, with Witczak and Hirsh models being the most widely accepted. These models have been evaluated in the present study, on the basis of 352 data points from eight asphalt concrete mixtures that were tested between −5 and 60 °C. A new model is also formulated which improves predictions of the previous ones for Spanish mixtures, even though it is a relatively simple equation that requires very limited binder rheological data compared to Witczak and Hirsch models.