Sustainable Concrete-Based Interventions for the Structural Retrofitting of Manifattura Tabacchi in Bologna by Pier Luigi Nervi

In the framework of the conservation of twentieth-century heritage, the re-functionalization of the Manifattura Tabacchi in Bologna into technopole represents an opportunity to reflect on intervention strategies and materials for the preservation of concrete-based architecture. Focusing on the Fabbricato Lavorazioni, a building of the industrial complex realized by Pier Luigi Nervi during the 1950s, the paper presents structural measures that involve the use of innovative and fibre reinforced cementitious materials as a sustainable alternative to traditional strengthening interventions. The proposed structural solution involves the use of prefabricated elements made of high-performance and fibre reinforced concrete, thus ensuring an optimized use of materials. For the local shear strengthening, the use of carbon fibre reinforced polymer rods is proposed, according to the near-surface mounted technique. The presented interventions are compared with the actual steel-based design, following environmental and economic sustainability criteria including the life cycle of the materials and the cost estimation. The results show that the reinforced concrete solution is more advantageous both in economic and environmental terms. Indeed, the introduction of reinforced concrete shear walls mitigates the seismic actions on the original structure, with a consequent reduction of local interventions and the improvement of the overall sustainability.