SON-REB method

The SONREB method is based on the combination of the results obtained from the rebound hammer and ultrasonic tests carried out on the same areas, correlating the rebound index (REBound) and the velocity of the ultrasonic waves (SONic), with the compressive strength of concrete. The correlation is obtained through an appropriate calibration of the relationship that links these three quantities by means of a statistical regression of the experimental values.
The SONREB method aims to compensate for the inaccuracies of the two non-destructive methods used, the moisture content, which leads to an underestimation of the rebound index and an overestimation of the ultrasonic velocity, and the age of the concrete, which increases the rebound index and reduces the ultrasonic velocity.
By carrying out compression tests on specimens taken at the same points where the non-destructive tests were carried out, an increased correlation accuracy is obtained.
In case no direct compression data are available for the tested concrete, correlation curves from the literature are used.

Reference standard: UNI EN 12504-4:2021; UNI EN 12504-2:2021.