Concrete cover characterisation using dynamic acousto-elastic testing and Rayleigh waves
Résumé
This paper presents the application of surface Rayleigh waves in nonlinear dynamic acousto-elastic testing
for the nondestructive evaluation of the concrete cover. Numerous physical phenomena, such as conditioning
and slow dynamics, characterising the dynamic non-classical nonlinear elastic behaviour of
many types of micro-heterogeneous solids, were observed in concrete. Rayleigh waves were used as
probing waves to evaluate the effect of local property changes in a concrete cover. The proposed method
was validated for two typical problems of concrete durability, in a case of thermal damage – distributed
micro-damage – and in a case of carbonation – surface problem with determination of the carbonation
depth. In both cases, the results showed that the relative variation as a function of material changes of
the nonlinear parameters was much higher than that of the ultrasonic pulse velocity.