Regional road engineers also use Schmidt’s hammer when diagnosing and assessing the structural and technical condition of bridge structures. Schmidt’s hammer is a hardness tester, i.e. a mechanical device for measuring the compressive strength of embedded hardened concrete. This is non-destructive testing, which means that it is not necessary to “tear down” the structure or drill holes, but the testing is performed directly on the structure. The advantages of measuring with a Schmidt hammer lie mainly in small dimensions, low weight and easy operation. Thanks to this device, employees of the Diagnostics, Quality and Complaints Department of SÚC PSK can quickly, easily and practically at any place determine the strength characteristics of the bridge concrete. The principle of measurement is the rebound rate of the impactor from the surface of the tested concrete structure. The hardness tester is pressed against the cleaned and sanded test surface in a smooth movement, the striker is locked and the measured value is read from the dial. One measurement consists of at least 9 such blows, the results of which are averaged and the age of the concrete and the direction of the blows are also taken into account.
