Crack propagation characterisation of bituminous mixtures using a four-point bending notched specimen test

Fracture behaviour of bituminous mixture has been increasingly studied in the last decade for a more comprehensive and detailed approach which could be taken into account in the pavement design process. This study presents an investigation at the Université of Lyon/Ecole Nationale des Travaux Publics de l'Etat (ENTPE) on fracture behaviour of bituminous mixtures during crack propagation. The four-point bending notched fracture test which has been designed at ENTPE was used. A quite new methodology, which makes it possible to characterise fracture behaviour of tested mixtures during crack propagation tests, has been proposed and applied for these tests thanks to an improved crack length determination approach based on inverse analysis. According to this methodology, different fracture parameters such as fracture toughness and fracture energy can be evaluated at different moments during the crack propagation test for a given advancement of the crack tip.