Abstract

The conservation work carried out on the “Santa Maria degli Angeli” Orphanage in Castelgrande (Potenza, Italy) following the earthquakes of 1980 and 1981 is a good example of the need to evolve and refine the concept of seismic consolidation and upgrade of monumental heritage; this, considering not only the needs of the current structural calculation, but also those related to the design of durability and overall technological quality. Built from 1878 around the original nucleus of a chapel, the seminary, then an orphanage, kindergarten, nursery school, sewing workshop and school, and summer mountain colony, constitute a precise landmark in the landscape of the ancient town of Castelgrande. Severely damaged by the earthquakes, it was declared unfit for use and evicted, and is still abandoned today.Immediately afterwards, radical refurbishment works were carried out on it, with the creation of sub-foundations, injections and tackles with reinforced concrete slabs for the load-bearing walls, replacement of the floors in steel beams and bricks with reinforced concrete floors, replacement of the wooden roofs with others of the same configuration, but in steel beams and clay tables, with a reinforced concrete slab above. The workings were not completed due to lack of funds and those performed so far show today serious pathologies (in particular the corrosion of the reinforcement of the joist of the floors and of the steel beams) as result of the lack of attention to fundamentals of materials science and of durability. Based on the current legislation and calculation methods, the research verified the seismic vulnerability of the building and proposed the necessary corrective actions: in particular, the replacement of the roofs with others, lighter and more durable, made of laminated, conditioned local Quercus cerris wood. A new destination has been proposed, linked to the presence of the Astronomical Observatory, and its upgrade to nZEB has been designed, in respect of its monumental features.