Calibration and Validation of a Comprehensive Constitutive Model for Asphalt Mixtures

A nonlinear thermoviscoelastic, thermoviscoplastic, and thermoviscodamage constitutive model was developed recently to predict the response of asphalt mixtures under loading. This paper presents a systematic approach to determine the parameters of the model. The paper also demonstrates the efficacy of this approach through the calibration and validation of the model through various tests conducted on fine aggregate mixtures (FAM) and full asphalt mixtures. The dynamic modulus test was conducted to obtain linear viscoelastic model parameters while repeated creep-recovery tests were performed to obtain nonlinear viscoelastic and viscoplastic parameters. Viscodamage model parameters were obtained through the constant strain rate test. Once the model was calibrated, it was validated through a comparison of the predicted results with measurements from repeated creep-recovery tests conducted at various combinations of recovery times and temperatures. The predicted responses for FAM and full asphalt mixtures on the basis of the model were found to be in good agreement with the experimental data. Model parameters obtained on the basis of laboratory testing provided useful insights into the relationship between FAM and full asphalt mixture responses and the material properties that affect these responses.