In the field of non destructive testing of concrete structures, several regulations propose correlations between cubic compressive strength and ultrasonic pulse velocity or pull out extraction force respectively. These correlations are expressed by means of coefficients derived from calibration through destructive tests carried out on cores.
Aiming at evaluating the reliability of correlations in predicting concrete compressive strength, an experimental campaign has been started. Several concrete cubic specimens of different strength classes have been prepared and non destructive tested. Moreover, 16 cores have been extracted from the cubic specimens and ultrasonic and compressive tests have been carried out on them. Ultrasonic testing has been performed on both cubic specimens and cores in order to assess the influence of specimen form and dimension on the ultrasonic waves propagation.
In this paper results of the experimental campaign are presented and discussed
