Qualification method for the reinforced concrete structure

The study aims to show a recovery intervention of reinforced concrete buildings, that present signs of decay and deterioration. In the reinforced concrete structures, the most important properties can be obtained using the “destructive” tests (that require a local removal of material) and “non‐destructive” tests such as the sclerometer test, the ultrasonic test and the combined method called “SonReb”can be used. The combined results from different “nondestructive” tests are very interesting instruments to assess the concrete strength. This methodological approach can help to reduce the possible errors when using the sclerometer and ultrasonic tests separately; in this way, the combined method called “SonReb” (SONic + REBound) was developed. Using a combined method it is possible to balance some of the errors made when the two methodologies used separately. The above defined methodology has been tested on a building which is located in Matera (Italy): the “Annunziata” Brickwork; it was built in 1953 and it started the production in 1955. The kiln was built using a reinforced concrete structure and brickwork for the external envelope; the roof was realized using wooden structures. The diagnostic tests have shown a suficiently high ultrasonic speed and homogeneous surface values for all the pillars of the lower and middle level, but bad conditions for the upper level. These data were compared with the method “SonReb” to improve the qualitative interpretation of results. This approach is useful for classifying the pathological events of a building and to implement the solutions to improve the durability of a recovery intervention.