Non-contact surface wave testing of pavements using a rolling microphone array
نویسندگان
چکیده
We present experiments where a multichannel array of microphones and an automatic source are attached on a small trolley so that measurements can be taken almost continuously while moving. Measurements on asphalt or concrete pavement layers are based on supersonic leaky air-coupled surface waves. Results show that microphones can be successfully used to measure surface wave dispersion curves even while moving along the surface. We also demonstrate that the same approach can be applied to softer granular pavement layers utilizing the evanescent acoustic field in the air close to the soil surface. This opens up the possibility for faster on-the-fly surface wave testing of pavement layers since surface contact is no longer required. Résumé Nous présentons ici des expériences réalisées avec un dispositif mobile où sont attachés plusieurs microphones et une source à déclenchement automatique, permettant des mesures multicanaux pratiquement continues au fur et à mesure du déplacement. Les mesures sur les couches de chaussée asphalte ou béton utilisent les ondes de surface de fréquence supersonique couplées à travers l’air. Les résultats montrent que les microphones permettent de mesurer les courbes de dispersion des ondes de surface même quand le dispositif se déplace. Nous montrons aussi que la même approche peut être appliquée pour des revêtements granulaires moins rigides, en utilisant cette fois le champ acoustique évanescent dans l’air proche de la surface du sol. Cela ouvre la possibilité de contrôler rapidement les couches de chaussées, puisque le contact direct avec la surface n’est plus nécessaire.
منابع مشابه
Air-coupled microphone measurements of guided waves in concrete plates
Quality control and quality assurance of pavements is today primarily based on core samples. Air void content and pavement thickness are parameters that are evaluated. However, no parameter connected to the stiffness is evaluated. There is a need for fast and reliable test methods that are truly non-destructive in order to achieve an effective quality control and quality assurance of pavements....
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