Since the development of Cross Laminated Timber (CLT), there has been a surge in interest in massive timber buildings. Furthermore, recent conceptual and feasibility designs of massive timber towers of 30 or more stories indicate that performance of mass timber structural elements can compete with other building materials in the commercial industry (MGB Architecture and Design et al.). However, in order for massive timber to penetrate the commercial market even further, a solution is needed for long-span massive timber floor systems. Unfortunately, CLT falls short in this area and is unable to span long distances. The hollow massive timber (HMT) panel presented in this thesis offers one potential long-span solution.
Cross laminated timber (CLT) has become very popular for all types of structures all around the world in last years. CLT consists of uneven number of plank layers oriented in 90° angle to each other and bonded together. Various types of adhesives and technologies are used for bonding and manufacturing of final product. In some cases, gluing is not ideal manufacturing method and there is a demand of other manufacturing processes. Mechanical jointing is logical result of current research at the Czech Technical University. Research is focused on developing and verifying mechanical behaviour of mechanically jointed CLT solid wood panels. Sets of experiments focused on mechanical behaviour of these mechanically jointed CLT panels were performed. This paper summarizes results of wall, floor and timber-concrete composite elements, which have been tested.
Due to the high volume of timber required for manufacturing, the production of cross-laminated timber (CLT) panels could be an appropriate destiny for the existing surplus of pinewood presently available in Uruguay. Although wood construction is uncommon in this country, there are some companies with the capacity to adapt their production to new products such as CLT. This work evaluates the properties of CLT panels manufactured in Uruguay with local pine (Pinus taeda and Pinus elliiottii) from forest plantation thinning, which typically present low mechanical properties. Boards and panels were mechanically tested and the mechanical properties were determined, showing a strength class lower than C14. A numerical model, using the finite element method, was developed and the numerical results were compared with the experimental values. The results provided a first approach to the conditions and limitations of the use of CLT panels for building floors, produced under the current manufacturing conditions in Uruguay.
In-plane shear and planar shear due to out-of-plane bending are important properties for the design of CLT-type floor systems. Properties of CLT-type panels are influenced by the orientation of the layer’s major stiffness directions and the properties of their layers. The layers are influenced by their characteristics, laminate aspect ratio, growth ring orientation and edge-gluing. In order to utilize the mechanical potential of CLT-type panels, it is necessary to understand the effects of layer and laminate properties on CLT performance. CLT and CLT-hybrid panels were tested in planar and in-plane shear tests. The shear properties were evaluated using static and modal test procedures, the accuracy of non-destructive test methods was evaluated. Relationships between specimen properties and the characteristics of laminates and layers, such as aspect ratio, growth ring orientation and edge-gluing, were established.