Residential housing at beginning of XX century: Study of material, technological and structural features for its conservation

The research faces the study of the specificity of material, technological and structural features of residential housing of first decades of XX century referring to mixed structure buildings, whose particularity is determined by progressive combined use of "modern" elements and materials with "traditional" techniques and construction technologies. It is a "new" building typology, whose experimental and innovative attitude has produced, in the time and in the continuity of its use, a series of specific problems connected with its conservation. The study, getting started from social-economical and historical-cultural themes which determined development of new technologies, underlines the process of material-technical-technological-structural evolution generated by gradual introduction of new materials and substitution in a first time of single elements of building, then of entire parts and finally of the entire masonry box. In this way the research examines constructive conception of mixed structure building, its progressive transformation and typological-technological-structural features of single elements and/or subsystems, highlighting potential "points of crisis" which characterize decay processes specific of define construction "type". Such organised knowledge represents first stage of a vaster study aimed to determine physical, technical-technological and codes related decay processes and to define criteria for maintenance, conservation and codes complying of this building heritage.