Ultrasonic test methods for assessment of concrete strength during construction

The aim of this study was to evaluate an ultrasonic method as a technique for early compressive strength diagnosis of concrete during curing time. It was studied how signal travel time correlate with the concrete strenght at different curing time. Both compressive and ultrasonic tests were carried out, in order to evaluate the correlation between the ultrasonic parameters and the in time increase of compressive strength. Several cube specimens were made using 9 different mix-designs. Some mathematical expression of the correlation between compressive strength and acoustic parameter were proposed and discussed. Results show that the analysis of ultrasonic velocity V at 28 days curing time can make possible an accurate determination of concrete mechanical characteristics