Timber-Timber-Composite (TTC) beam long-term behaviour. Full scale experimental campaign and simplified analytical model

Abstract

[Abstract] The variability of the physical and mechanical properties of wood requires that the analysis of its long-term behavior take into account all the factors capable of modifying these properties. The environmental conditions of humidity and temperature are factors that alter these properties, conditioning long-term behavior, a situation that is especially decisive in the case of structural elements in bending. The design standards establish simple corrective factors based on the type of environmental exposure that allow creep deformation to be estimated in a final stage from an initial instantaneous deformation value. A new analytical model is proposed that allows estimating the behavior at any stage from the knowledge of the environmental conditions to which the structural element has been subjected. The model is applied to different elements in various environments, from camera control situations to outdoor situations of 3-year seasonal cycles. In all cases, the precision of the model and the simplicity of its use are verified due to the basic factors on which it is based.