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Monitoring of cracking and healing in an ultra high performance cementitious material using the time reversal technique / S. Granger in Cement and concrete research, Vol. 39 N° 4 (Avril 2009) 

Public ISBD [article]  in Cement and concrete research > Vol. 39 N° 4 (Avril 2009) Titre : Monitoring of cracking and healing in an ultra high performance cementitious material using the time reversal technique Type de document : texte imprimé Auteurs : S. Granger, Auteur Année de publication : 2009 Langues : Anglais (eng) Mots-clés : Acoustics;  Time  reversal;  Cracking;  Healing;  Non-destructive  technique Résumé : A non-destructive testing technique based on the time reversal principle is applied to cementitious materials. Preliminary results are presented showing the reversibility of wave propagation and that focusing by time reversal is feasible in cementitious materials. Then, the technique is implemented on a mechanical test in order to monitor the cracking process of a concrete specimen loaded under three point bending. The acoustic mirror permits qualitative monitoring of the propagation of a crack by analyzing the focusing of a reference signal on a sensor placed near the expected crack path. A decrease of energy and of amplitude of the focused signal is observed upon cracking. Then, the specimen made of a material with high capabilities of self healing, is immersed in water, and healing processes are monitored. The results show a recovery of signal focusing upon healing. Comparisons with mechanical test data indicate that the method is sensitive to the variation of stiffness of the structure due to crack propagation and crack healing. ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science/article/pii/S0008884609000076 [article] Monitoring of cracking and healing in an ultra high performance cementitious material using the time reversal technique [texte imprimé] / S. Granger, Auteur . - 2009. Langues : Anglais (eng) in Cement and concrete research > Vol. 39 N° 4 (Avril 2009) Mots-clés : Acoustics;  Time  reversal;  Cracking;  Healing;  Non-destructive  technique Résumé : A non-destructive testing technique based on the time reversal principle is applied to cementitious materials. Preliminary results are presented showing the reversibility of wave propagation and that focusing by time reversal is feasible in cementitious materials. Then, the technique is implemented on a mechanical test in order to monitor the cracking process of a concrete specimen loaded under three point bending. The acoustic mirror permits qualitative monitoring of the propagation of a crack by analyzing the focusing of a reference signal on a sensor placed near the expected crack path. A decrease of energy and of amplitude of the focused signal is observed upon cracking. Then, the specimen made of a material with high capabilities of self healing, is immersed in water, and healing processes are monitored. The results show a recovery of signal focusing upon healing. Comparisons with mechanical test data indicate that the method is sensitive to the variation of stiffness of the structure due to crack propagation and crack healing. ISSN : 0008-8846 En ligne : http://www.sciencedirect.com/science/article/pii/S0008884609000076