Computed tomography in the fatigue test analysis of an asphaltic mixture

This work applies the computerized tomography technique to the study of an asphaltic mixture. It was required to detect and follow the evolution of a crack, when this mixture was submitted to fatigue tests. The fatigue tests to produce stresses were done in a diametral compression equipment of repeated loading. The trajectory of a crack is influenced by original voids in the specimen; it may be noted that troughs exist in all tomographic images at the same positions and, as these could be due to voids, with a sufficient sequence of applied loads they would be transformed into a small crack that would increase in size, causing the collapse of the specimen. It was possible to detect and follow the evolution of a crack as the 900 blows were applied to the phantom. It was also noted that the crack begins to appear in the central region of the specimen and is propagated in the direction of the applied load.