The results of an experimental programme on the structural behaviour, fire behaviour, and fire resistance of CLT rib panels are presented. The floor system consists of cross-laminated timber (CLT) plates rigidly bonded to glued-laminated timber ribs by means of screw-press gluing.
The experimental programme comprised ultimate-load tests at normal temperature as reference tests and full-scale fire resistance tests on four cross-sections. In addition to the reference tests, shear tests of the glue line between CLT plate and glued-laminated timber rib were performed for analysis of the cross-sections’ composite action.
The results of the reference tests show good agreement with results based on the simplified method according to EN 1995-1-1  and its final draft of CLT design . The importance of the glue line’s quality was confirmed. The fire resistance tests show results on the safe side compared to predictions of the fire behaviour according to EN 1995-1-2  and its actual draft . However, the fire resistance was underestimated due to conservative assumptions about the composite cross-section’s structural behaviour.
The experimental programme addressed the fire behaviour and fire resistance of CLT rib panels currently not covered in standards. The project’s overall aim is the development of design rules in fire for EN 1995-1-2.
International Association for Bridge and Structural Engineering Symposium
September 19-21, 2018, Nantes, France
Contemporary structures are required to be earthquake-resistant, sustainable and flexible to changing occupancy needs over time. Hybrid wood-based construction systems are promising solutions for modern buildings and research for cost-efficient systems is underway to compete with more traditional and widely spread non-wood building systems. This paper presents an innovative modular and prefabricated wood-based hybrid construction technology. It is a dry solution obtained by fastening on-site steel frames and composite CLT-steel members using only bolts and screws. The main results obtained from a comprehensive experimental programme with focus on the in-plane and out-of-plane behaviour of floors are reviewed. The influence of connections on the response of floors is discussed. The findings are of practical relevance with direct impacts on other applications.
Hybrid construction systems proved to be valid structural solutions for the implementation of multi-storey buildings, especially if they require only the assembly of prefabricated and modular building elements. The structures here considered are designed to make different materials - firstly steel and timber - structurally collaborate, in order to develop a construction system with marked performance and architectonic flexibility features. Such systems can make the most of the heavily industrialized construction technology typical of steel systems, as well as of the advantages offered by CLT panels -lightness and structural stability- in which the timber element is recognized as an eco-friendly and eco-compatible material. Furthermore, in a sustainable urban development prospective, the use of cross-laminated timber panels, in short CLT, is recommended because wood is one of the fewest materials which has the capacity to isolate and store CO2 for a long period of time.