PRELIMINARY INVESTIGATION ON THE STRUCTURAL AND HYGROTHERMAL PERFORMANCES OF CLT WITH AIRGAPS

Paper in proceeding, 2025

Cross laminated timber (CLT) has been a major contributor to the expansion of the technical possibilities of timber constructions. While CLT has advantages, the production of CLT requires extensive raw material input compared to the actual needs regarding structural capacity. It is expected that the required load bearing capacity can be achieved by using less raw material if the timber lamellas are arranged properly with gaps in between. Different configurations with different material efficiency result in different structural and hygrothermal performance of the panels. The overall goal of the project described in this paper is to investigate the raw material saving potential for a multi-story structure with CLT panels with airgaps. For this purpose, the shear, bending, and water vapor permeability performances of 3-ply and 5-ply CLT panels with various airgap configurations have been investigated in experiments and in numerical and analytical models. Based on the results, the load bearing structure of an 8-story residential building was designed with CLT panels with airgaps. The structure was designed to satisfy the performance requirements according to Eurocodes and for moisture safety. The result shows that the material saving potential is at maximum 46% for the floor and 29% for the wall. In order to further optimize the CLT panels and verify the results, more experiments on more variety of airgap configurations will be needed.