Abstract:
An important segment of the Romanian urban population, similar to other Eastern European countries, lives in collective residential apartment buildings made using large prefabricated concrete panels. Most of these structures were built between 1960 and 1989 and present major issues concerning aesthetical aspects, lack of internal space, problems related to thermal comfort and, last but not least, weak energy efficiency.
Building adaptation is a well-known established solution for rejuvenating an existent structure and offering new living spaces to the population. On this note, over-roofing is one of the practices most popular among structural engineers, as together with over-cladding it offers an integral solution for rejuvenating an existing building.
Moreover, using steel as base material for these over-roofings is common, due to its flexibility, long spans and easy erections. Also, steel is known for its recyclability quality, making the structure more sustainable, impact on the environment being a raising concern nowadays. On this idea, cold-formed steel has become preferable to hot-rolled one. There are several benefits to using cold-formed steel sections, including reduced material, fabrication, transport, and construction costs, and a higher strength to weight ratio compared to hot-rolled steel. Not to mention, a better behaviour in seismic areas.
However, cold-formed connections are less easy to design, detailing becoming a challenge for most engineers.
Thus, the aim of this thesis is analysing the behaviour of these cold-formed connections and to offer the best solutions for these over-roofing structures. Moreover, the scope of this study is not only to improve the structural techniques used for building these building adaptions but to improve the quality of life of the occupants by offering them a holistic solution from structural and energetic point of view.
