Change in fatigue behavior of asphalt hot mixes produced with asphalt rubber binders

Abstract

Fatigue life of asphalt hot mixes is given as a function of both stiffness and tensilestrains induced in the bottom of the wearing courses of flexible pavements. In conventional as-phalt hot mixes the increase of stiffness leads to a decrease of fatigue life. However, this work shows that there is an increase of both fatigue life and stiffness of asphalt rubber hot mixes in comparison with the asphalt hot mixes produced with straight binders. In this work laboratory tests were performed in asphalt hot mixes with dense and gap gradation produced with straight binder (AC 50/70) and asphalt rubber binder manufactured by the wet process. Resilient mod-ulus and fatigue life tests under four point bending procedure were used to determine the me-chanical behavior of studied mixtures. The results show that the use of asphalt rubber binder produced an increase of both fatigue life and stiffness of the studied mixtures.