Assessment of cracks detection in pavement by a distributed fiber optic sensing technology

International audienceThis paper presents the feasibility of damage detection in asphalt pavements by embedded fiber optics as a new non-destructive inspection technique. The distributed fiber optic sensing technology based on the Rayleigh scattering was used in this study. The main advantage of this technique is that it allows to measure strains over a long length of fiber optic with a high spatial resolution, less than 1 cm. By comparing strain profiles measured at different times, an attempt was made to link strain changes with the appearance of damage (cracking) in the pavement. This non-destructive method was evaluated on accelerated pavement testing facility, in a bituminous pavement. In our experimentation, the optical fibers were placed near the bottom of the asphalt layer. The application of 728 000 heavy vehicle loads (65 kN dual wheel loads) was simulated in the experiment. Optical fiber measurements were made at regular intervals and surface cracking of the pavement was surveyed. After some traffic, a significant increase of strains was detected by the optical fibers at different points in the pavement structure, before any damage was visible. Later, cracking developed in the zones where the strain profiles were modified, X. Chapeleau et al. thus indicating a clear relationship between the increased strains and crack initiation. These first tests demonstrate that distributed fiber optic sensors based on Rayleigh scattering can be used to detect crack initiation and propagation in pavements, by monitoring strain profiles in the bituminous layers

Explore 2070 : quelle utilisation d’un exercice prospectif sur les impacts des changements climatiques à l’échelle nationale pour définir des stratégies d’adaptation ?

Les changements climatiques projetés à l’horizon du milieu du XXIe siècle pourraient avoir des impacts importants sur la disponibilité en eau en France. L’étude prospective Explore 2070, pilotée par le ministère chargé de l’écologie, a ainsi mis en évidence la nécessité de quantifier et d’anticiper ces changements, et de construire des stratégies d’adaptation pour limiter leurs conséquences négatives sur les hydrosystèmes et les activités humaines. Cet article analyse dans quelle mesure ces travaux ont pu contribuer à la sensibilisation des acteurs de l’eau et à la réflexion sur l’adaptation au changement climatique en France