NDT ultrasonic evaluation of early compressive strenght in SCC

The aim of this study was to evaluate a ultrasonic method as a technique for compressive strenght diagnosis particularly during curing time. We focused our attention on mid-range strenght SCC. We studied how signal travel time and signal amplitude attenuation correlate with the material. Both compressive and ultrasonic tests were carried out at different curing times, in order to evaluate the correlation between the ultrasonic parameters and the in time increase of compressive strength. Several cube specimens were made using 10 different mix-designs. Some mathematical expression of the correlation between compressive strenght and acoustic parameters were proposed and discussed. Results show that analysis of ultrasonic velocity V, better than attenuation amplitude AA, make possible an accurate determination of SCC mechanical characteristics, also at short curing.