Stiffness and fatigue properties of asphalt: effect of the bitumen type and the bitumen content

In the context of laboratory fatigue performance evaluation of bituminous materials, the bitumen type is the most significant parameter. Other material composition parameters, like bitumen content and asphalt void content also affect the performance. From a material specification point of view, the testing device is also known as an important factor that induces variability in standard fatigue properties evaluation. This paper presents an experimental study on stiffness and fatigue evaluation involving six asphalts with the same aggregate size distribution. Stiffness evaluation was done using the bending test on trapezoidal cantilever beam with a temperature and frequency sweep. For fatigue, two types of fatigue device are used. The uniaxial tension-compression test on cylinder has been chosen to obtain a homogeneous damage process since the localization of the failure zone. In the same time, the trapezoidal cantilever beam protocol has also been performed in reference to the European standards fatigue performance evaluation. Some aspects such as the influence of specimen geometry on self heating during fatigue are discussed. The effects of bitumen type and its void content on asphalt fatigue are clearly demonstrated using both new and classical analytical tools. For the covering abstract see ITRD E157233