Experimental technological solutions in mixed structure buildings of the ‘50s in Sicily

The paper aims to explore the history of construction in the „50s in Italy. In this period, while in the rest of Europe, the use of framed structures was well established, in Italy, reinforced concrete found it hard to be understood and used as building system. R.C. pillars and beams were combined with masonry thickness also playing load-bearing function. These structures, therefore, defined “mixed” or “hybrid” were completed with reinforced concrete technical elements or hollow bricks slabs following, in most cases, static patterns of traditional building techniques. The paper reports the studies carried out on the rural villages built in Sicily in the „50s, made of service buildings (church, school, restaurant, police barracks, basic necessities shops, etc.). This study was conducted through the prior consultation of manuals, books and journals of the period and then by a deep research of technical documentation preserved in the archives of contractors. By means of the project drawings, metric calculations, structural calculations and the direct survey of the buildings, materials and construction techniques were analyzed. In particular, it was possible to devise the static schemes for two-levels buildings intended for residential or services, all based on the integration of the load-bearing masonry structure with reinforced concrete structures variously positioned and generally only used to decrease the light of hollow bricks slabs and roofs. Particularly interesting were, above all, the churches, because of the great spans, about 10 m, needed r.c. load-bearing framed structure, but still oversized and supported by considerable thickness continuous walls (about 50 cm). The main technological innovations were found in these buildings in the various experimental solutions for the realization of the two-sloped roofs. “Mixed” truss were experienced for roofs, consisting of prefabricated struts (hollow bricks with reinforced rods inside and concrete casting) well-known as type SAPAL and iron chain embedded in concrete beam, casted at the eave. Technological experimentation corresponded to the specific calculations for new solutions. This paper provides a contribution to the enrichment of knowledge on the history of modern Italian architecture through case studies, as yet unpublished, fully documented and rich in details of construction.