Il vetro strutturale - Parte I

Over the last years, glass has found an increasing diffusion in buildings. Reasons are mainly due to technological progress, which has improved mechanical characteristics of glass, making it the absolute protagonist when the designer searches for an architectural expression oriented to transparency and lightness. Parallel to technological progress, the increased theoretical scientific knowledge of the material allows for designing and building more and more complex architectures. The paper, divided into two parts, introduces base design of glass structural elements and presents an innovative solution for building laminated glass beams strengthened with FRP bars. The authors have already dealt with both topics at greater length in the volume “Il vetro come materiale strutturale”, published by Edizioni Polistampa, Florence. The first part describes main mechanical properties of glass and types of glass utilized for structural applications. Then, the authors discuss issues linked to the fragility of glass, and how they make difficult the use of glass for main load-bearing elements. Hence, a solution can be found in utilizing laminated glass elements, formed by two or more glass plies bonded together with a thermoplastic material, and/ or in coupling glass with other structural materials. The second part, which will be published successively, glass beams strengthened with FRP bars. Such beams, which are conceptually analogous to reinforced concrete beams, succeed in satisfying requirements of strength, stiffness and safety, while maintaining almost unchanged the transparency.