The restoration of the concrete architecture of 20th century. The Torre Delle Nazioni in the Mostra d’Oltremare in Naples

ABSTRACT The conservation of the architectural heritage of twentieth century in reinforced concrete is a need that can no longer be deferred. The difficulty of intervening on a material that has been widespread since the first decades of the last century requires a careful evaluation to determine the residual strength as a function of the useful life. Furthermore, there are considerable problems deriving from the poor packaging of concretes, both for reasons of lack of technological knowledge and of a speculative nature, particularly in Italy in the post-war period. To these considerations on the vulnerability of concrete are added those deriving from the seismic as well as static risk. In recent decades, an important research has been developed and consequent production of high-tech nanotechnological concretes that allow an ever greater possibility of intervention to safeguard these structures. In this sense we describe the recovery of the Tower of Nations, one of the most representative buildings of the Mostra d’Oltremare, which is one of the greatest examples of urban and architectural intervention in Naples in the Fascist period.