INTERACCION ACUSTICA/ESTRUCTURA EN LOS EDIFICIOS DE MADERA ACOUSTIC/STRUCTURE INTERACTION IN TIMBER BUILDINGS
Acoustic and structural performance are closely related in mass timber buildings. The low density of the panels related to their high stiffness are the reasons that made Cross Laminated Timber successful in high risk seismic areas; nevertheless, these same features are the reasons for the relatively poor sound insulation that they provide as bare structural elements. This paper investigates the aspects of mass timber construction in which the optimization of the one is detrimental to the other. Since in both disciplines a relevant part of the transmission of vibrations (or loads) is carried out by the metallic connections, the work focusses on the acoustic and structural performance of CLT junctions, through the analysis of acoustical and structural tests. First, the influence of the kind and number of screws, hold downs and angle brackets is analyzed in relation to the structural constraints and their acoustic performance. The results show that different connection systems affect the vibration transmission in a relevant manner and must be compensated through an accurate design of the internal linings. Second, the use of the resilient interlayers at the wall floor junction is discussed. If on one hand it provides a significant increase of the vibration reduction index, on the other the application of this layer can reduce the ultimate load capacity of the junction up to 38% suggesting that the choice of the soundproofing profile must be accurate.