Modeling and analysis of susceptibility to permanent deformation in asphalt mixtures

Abstract

Permanent deformation of asphaltic mixtures in the Metropolitan Area of Valle de Aburra – Antioquia, which are built under IVIAS’ specifications (Instituto Nacional de Vías) and Valle de Aburrá, were studied by employing a constitutive model proposed previously. This model had proved to be effective in predicting deformations of asphaltic mixtures in the United Kingdom under different kinds of loads; under uniaxial and triaxial conditions and temperatures at intervals between 0 ºC and 40 ºC. For the specific case of Valle de Aburra, temperatures ranged between 20 ºC and 50 ºC and the model was implemented in order to predict susceptibility to permanent deformation. By means of an experimental study on mixtures, it was found that their behavior under steady state condition followed the model modified by Cross2, thus mixtures showed a visco-linear and non-linear behavior at low and high stress levels, respectively. It was observed that under loading and unloading conditions, there is a temperature dependence on the material behavior, which was properly predicted by Arrhenius3 under the studied temperatures interval. When modeling mixtures behavior, it was found that that their strain susceptibility varied widely depending on the constituent materials, especially on the aggregate, in spite of the fact that the mixtures are similar.