DIAGNOSIS OF THE CRITICAL STATE OF CONCRETE

Reinforced concrete is the material with which it is built much of the architectural heritage, ordinary, but also monumental the last 100 years. Recently, there has, however, found that it is not the eternal material that you dreamed when you started to use it massively and with time degrades by various phenomena that are often attributed to the degradation that attacks the plates, but is not this the only cause which can lead to damage of the same, also the load cycles to the limits of rupture may determine, mechanically, a loss of capacity. And this, for example, the case of a building subject to an earthquake that while not causing collapse or breakage evident engages the concrete severely. The concrete thus "reduced" is still able to withstand the same loads? Is there a way to figure out when it is exceeded a threshold of attention? In this paper we want to present the results of a campaign of investigations in the laboratory with ultrasound helps to create a first answer to these questions. The technique, suitably calibrated, may be used in all those cases in which it must operate on elements that have been subject to exceptional loads to evaluate properly the areas in which it is essential to the intervention.