Asphalt rubber mixtures in Portugal: fatigue resistance

This paper presents a study concerning the fatigue behaviour of asphalt mixtures with bitumen modified with high content of crumb rubber used in Portugal. For assessing the fatigue behaviour, four asphalt mixtures with high content of crumb rubber were used: two field bituminous mixtures - an open-graded and a gap-graded - both with granite aggregates; and two laboratory manufactured bituminous mixtures - an open-graded mixture with granite aggregates and a gap-graded mixture with crushed gravel aggregates. Since these types of mixtures are mainly applied in wearing courses, the effect of ageing in the fatigue behaviour of one of the studied asphalt rubber mixtures was also assessed through laboratory testing. It was concluded that all the materials have exhibited good fatigue resistance, in agreement with others previous studies. In the case of the aged gap-graded material, it was observed a slight reduction on the fatigue life comparatively to the un-aged one. For the covering abstract see ITRD E144473.