Abstract Summary
The construction industry contributes a significant percentage of CO2 emission globally. Therefore, using renewable structural materials is beneficial from a sustainability perspective. Building with timber has gained an unstoppable rise in popularity. After decades of dominance of concrete and steel civil engineering structures, the revival of timber structures started with low-rise residential buildings due to the limited size and mechanical properties of the raw timber material. However, the emergence of cross-laminated timber (CLT) in the 1990s made timber structures competitive against reinforced concrete and steel structures for multi-storey buildings as well. CLT is a prefabricated engineering wood product, usually composed of an odd number of crosswise glued layers. Besides being eco-friendly, CLT is characterised by outstanding strength, stiffness, fire resistance, esthetics, and speeds up construction. However, due to the high stiffness-to-weight ratio, lightweight long-span CLT floor systems are susceptible to vibration induced by human cyclic activities, such as walking, running and jumping. Excessive vibration can lead to occupants' discomfort or malfunction of vibration-sensitive equipment, such as lasers and microscopes. CLT floors are more complex when compared to monolith reinforced concrete floors. Connections between adjoining CLT panels, orthotropic properties of timber and crosswise layer arrangement can significantly affect modal properties of the assembled floor. Consequently, there is no simple analytical expression that can be used to determine structural modal parameters, such as modal mass, stiffness and damping, needed for vibration serviceability analysis of CLT floors. In this paper, an experimental modal analysis was carried out to identify modal properties of several CLT floors with different boundary conditions, the number of panels in a floor assembly and the inter-panel connections. Influence of the latter on the floor modal properties is particularly studied and discussed.
