Accelerated Discrete-Element Modeling of Asphalt-Based Materials with the Frequency-Temperature Superposition Principle

Abstract

This paper presents a methodology to reduce the computation time for discrete-element (DE) modeling of asphalt-based materials, based on the frequency-temperature superposition principle. Laboratory tests on the dynamic modulus of asphalt sand mastics and asphalt mixtures were conducted at temperatures of � 5, 4, 13, and 21°C and frequencies of 1, 5, 10, and 25 Hz, respectively. The test results of the asphalt sand mastics were fitted with the Burger's model to obtain the microparameters for DE models. To reduce the computation time of the DE modeling, the regular loading frequencies were amplified to virtual frequencies. Simultaneously, the Burger's model parameters (micro- parameters in DE models) of asphalt sand mastic at regular frequencies were modified to those at virtual frequencies on the basis of the frequency-temperature superposition principle. Because the virtual frequencies were much larger than the regular frequencies, the compu- tation time was significantly reduced by conducting the DE modeling with the virtual frequencies and the corresponding modified Burger's model parameters. The modeling work, which typically takes several months or years with the traditional methods, only took a few hours or less in this study. DOI: 10.1061/(ASCE)EM.1943-7889.0000234. © 2011 American Society of Civil Engineers. CE Database subject headings: Asphalts; Mixtures; Viscoelasticity; Discrete elements; Micromechanics; Temperature effects; Models. Author keywords: Asphalt mixes; Viscoelastic; Discrete-element method; Micromechanical modeling; Burger's model; Frequency- temperature superposition; Reduce computation time.