Prediction of asphalt mixtures’ behavior during their service life is a challenge due to its complexity andsensitivity to environmental and loading conditions. It has been proved that, when subjected to loadingconditions comparable with most pavement operating conditions, asphalt mixtures behave as linearvisco-elastic (LVE) materials. Traditionally the LVE behavior of bituminous material is modeled viacreep/recovery functions. In the past, several rheological models constituted by elastic and viscous elementsarranged in series or in parallel (analogical models) have been proposed and specified for bothbitumen and asphalt mixtures. The corresponding constitutive laws always involve first order derivativesof time with exponential type solutions but problems in setting parameters arise when both the creepand recovery behavior have to be modeled. In this paper it is shown that experimental creep data followa power decay law, rather than an exponential one. As a consequence, a simple fractional model is hereproposed for predicting creep/recovery behavior of asphalt mixtures with a small number of parametersand low computational efforts with respect to the classical analogical models. The proposed model isthen calibrated by a best fitting procedure on experimental data from creep and creep/recovery tests carriedout on asphalt mixtures under different load and temperature conditions.
|Numero di pagine||9|
|Rivista||Construction and Building Materials|
|Stato di pubblicazione||Published - 2012|
All Science Journal Classification (ASJC) codes