DAMAGE MEASUREMENTS IN CONCRETE VIA AN ULTRASONIC TECHNIQUE .1. EXPERIMENT

In this paper, the possible correlations between the mechanical and acoustical consequences of damage in concrete are investigated. The particular case of the compression test is chosen for many reasons among which, the strong elastic anisotropy induced by the degradation. Both the velocity and the amplitude of longitudinal or shear waves are measured on cubic specimens. In a first step, within the elastic domain, an acoustical anisotropy due to the porous nature of undamaged concrete is highlighted. Then, another form of anisotropy induced by damage (i.e. microcracks) appears. These two phenomena may exist simultaneously in real concrete.