Estudo da fadiga em misturas asfálticas por meio do ensaio cíclico de tração-compressão uniaxial.

Abstract

In Brazil, the most recurrent defects on the highways are cracking due to fatigue and permanent deformation. Among several causes, the appearance of cracks in the asphalt coating is mainly due to the repeated traffic loads, which considerably reduce the service life of the pavement, allowing water to enter the granular layers and road structure, leading to deterioration in a more accelerated. Laboratory tests are the main resource for the study of fatigue, traditionally the evaluation of fatigue is performed through the diametrical compression test, which admittedly presents limitations in the state of tensions developed. In many countries in Europe and North America, more efficient methods of predicting fatigue are already a consolidated reality. In this sense, this work aims to contribute to the dissemination of the new cyclic Fadiga-Traction-Uniaxial Compression test, which has not been carried out in Brazil, and to study the theory of Viscoelastic Continuous Medium Damage (S-VECD). By calibrating the S-VECD model with the uniaxial tensile-compression fatigue test it is possible to predict the fatigue performance of asphalt mixtures regardless of the shape and amplitude of the load applied to induce the damage. The fatigue tests were performed by diametrical compression, LAS and fatigue in the uniaxial traction-compression in order to study this phenomenon by the traditional and new methodology. The tensile-compression test was performed satisfactorily, with well defined rupture and obtaining the number of cycles that led the asphalt mixture to rupture.