Il recupero delle strutture in calcestruzzo in ambiente marino: Il caso del Ponte di Vivara a Procida

This text analyzes the issue of the recovery of the concrete in aggressive marine environment and specifies the methods of investigation and action taken to consolidate the Bridge of Vivara in Procida. The island of Procida was originated by eruptive activity of five volcanoes; the partial immersion and landslides along the south eastern part of the oldest, gave rise to the island of Vivara (0:32 sq km), characterized by the peculiar half-moon configuration that draws the evolution of the ancient volcanic structure, completed ashore from the promontory of Santa Margherita, in the center of which grows the wonderful stretch of water called Gulf of Genito. The connection between Procida and Vivara is provided by a bridge built in 1957, the structure, typical of the viaducts, is made using a system of prefabricated beams resting on reinforced concrete pulvinos and columns in concrete, founded on a system of plinths on the seabed. The advanced state of deterioration had affected the load-bearing capacity; therefore it was necessary to prepare a recovery intervention and technological seismic upgrading who have restored the functionality. The author illustrates the methodology used to develop the plan finding inquiries, project choices and the materials used, on the basis of the most recent legislation and research on the durability of reinforced concrete structures, cast in situ and pre-stressed, according to the exposure to aggressive agents of sea origin.