The paving grade bitumen used in the production of asphalt mixtures for roadconstruction is significantly able to affect the in-service performances of flexible roadpavements. It has been proved that, when subjected to loading conditions comparable withmost pavement operating conditions, bituminous binders behave as linear visco-elasticmaterials. The aim of this paper is to propose a model based on fractional differentialequations which is able to describe the behavior of bituminous binders in the linear viscoelasticrange.Shear creep testing and creep recovery testing were carried out over a range of temperaturesand by applying a stress level which makes it possible to maintain the response of the studiedbitumens within the linear visco-elastic region. It is shown that creep tests follow a powerdecay law, rather than an exponential one: it follows that the most appropriate operator fordescribing the constitutive law for bitumen is a fractional operator. The procedures used todetermine the model’s parameters from the experimental data are discussed.
|Number of pages||0|
|Journal||MECCANICA DEI MATERIALI E DELLE STRUTTURE|
|Publication status||Published - 2009|