La conservazione delle coperture in calcestruzzo armato nell'antica Pompei

Since the early decades of 20th century reinforced concrete has been widely used even in restoring archaeological ruins. This has taken place in ancient Pompeii starting from the 1930s and has continued up to the 1980s. The new technique has widely been applied in the (re)building of roofs, which would usually be made wing a system named SAP, and now are often collapsing. In most cases reinforced concrete structures were meant to substitute former wooden roofs which had been built, as soon as ruins were excavated, according to the traces left by ancient, beams or tiles. Reinforced concrete elements were usually built adopting shapes and dimension of those wooden elements which were to be removed. After few decades, most of these roofs have. turned out to be seriously afflicted by heavy and spread deterioration owing not only to weather causes but especially to low quality of materials which were often used in post-war times. A careful analysis has been carried out on a few significant cases (Vettii House, Julia Felix House, Silver Wedding Anniversary House) observing the current state of deterioration, testing materials and elaborating calculations in order to evaluate the level of structual safety. Results show a wide range of possibilities: in a few cases demolition has been necessary, while in most cases preservation and restoring have been successfully achieved.