Authors: Ismail Yousfi; Zoubeir Lafhaj; Richard Gagne
Addresses: Ecole Centrale de Lille, Department of Civil Engineering, Cité Scientifique, 59651 Villeneuve-d'Ascq, France ' Ecole Centrale de Lille, Department of Civil Engineering, Cité Scientifique, 59651 Villeneuve-d'Ascq, France ' Department of Civil Engineering, Sherbrooke University, 2500 boul. de l'Université, Sherbrooke QC J1K 2R1, Canada
Abstract: This paper focuses on the experimental characterisation of the elastic properties of sound and heat-damaged cement paste for different water contents: w/c = 0.3, 0.4 and 0.5. Damage is first assessed from mass density and wave velocity measurements. Linear acoustic methods were carried out but they did not permit an efficient evaluation of the earliest stages of damage. The goal of this research is to assess damage-induced non-linearities in the behaviour of heat-damaged cement paste. The method is based on the higher harmonic generation (HHG) technique. An empirical law is proposed to relate the non-linear elastic parameter β to the cement water content and to temperature. This is expected to give new insights in the field of non-destructive testing (NDT) methods; in particular, non-linear acoustic methods are expected to enable early failure diagnosis and thus reducing maintenance costs of infrastructure.
Keywords: nonlinear acoustic waves; heat damage; HHG; higher harmonic generation; cement paste; sound damage; ultrasonic characterisation; water content; mass density; wave velocity; elastic properties; nondestructive testing; NDT; early diagnosis; failure diagnosis; maintenance costs.
International Journal of Microstructure and Materials Properties, 2015 Vol.10 No.5/6, pp.321 - 339
Received: 06 Oct 2014
Accepted: 22 Jul 2015
Published online: 28 Feb 2016 *