This report presents bending tests performed on composite beams made from glulam beams and cross laminated timber (CLT) panels. The composite beam, with a T-cross section, represents a section of a floor element in a multi-storey CLT construction system. The shear connections used were made either of doublesided punched metal plate fasteners, either of inclined screws, or of a combination of both fastener types. The screws are used to secure the shear connection with double-sided nail plates with respect to possible separation forces between the glulam and the CLT. An additional test with a screw glued connection was made for comparison as the upper bound case in terms of composite action. The results show the beams with double-sided nail plates (with or without screws) achieved a very high level of composite action and an overall satisfactory behaviour. Almost full composite action was achieved for the screw-glued composite beam. A detailed design example of the beam element according to the Eurocode 5 and Finnish National Annex is presented.
The presented work deals with hygro-thermal numerical simulation and mould growth risk evaluation between concrete foundation and frame of multi-story building made of CLT element modules. Structural CLT modules represent an approach towards wood material utilization in construction as its strength achieves markedly higher values then common structural wooden elements and makes rapid erection of the building possible. Although there are great promises that the novel CLT structures will gain ground in high-rise buildings market with apparent benefits in sustainability and inhabitant comments regarding ambience and acoustics, it is important to analyse their structural health and hygro-thermal conditions. The highest risk of unfavourable hygro-thermal conditions is usually presented in location characterized by thermal bridge, such as foundation, window-wall, wall-roof and wall-floor junctions. It is also of significant importance to analyse junctions between materials, whether wood, composite, mortar or concrete. A certain combination of thermal and humidity conditions in exposed time causes mould growth initiation that may lead to deterioration of structural material and unhealthy indoor environment.
In this case study, the moisture content and air-flow in the junction and open space in structural design details between the first floor (of concrete) housing joint warehouse and technical spaces and the residential upper floors made of CLT modules is analysed. Conditions leading to probable moisture-derived mould issues and design parameters leading to sufficient ventilation according to Mould Index modelling are presented.
This research investigates a new structural system based on a central core of CLT (cross-laminated timber) panels to provide more useful multi-level timber buildings that are taller and with open floor areas. Because pinus radiata is a suitable timber for the manufacture of CLT panels, the system has the potential to add value...
In this chapter I describe a multidisciplinary research project into cross-laminated timber (CLT) panels which aims to transform the Australian construction and development industry and involves a range of key partners. This project will introduce CLT panels as a way to build with a lightweight prefabricated low-carbon construction system that is advantageous for urban infill and residential buildings. The challenge, research questions, and the advantages of this system are explained herein.
A worldwide interest in timber multi-storey buildings is expected due to the environmental advantages of timber construction when compared to buildings in concrete and steel. Cross-laminated Timber, or CLT, was developed in the early 1990’s and glues and clamps timber planks in alternate layers to form large panels. The cross-laminating ensures reliable strength and stability. CLT construction has been used successfully for the nine storey Murray Grove Stadhaus building in London and the ten storey Forte building in Melbourne . The paper proposes a new type of structural system that utilises CLT for buildings to twenty levels.
The floor plan with a central rectangular core and columns at the perimeter is similar to a typical RC commercial building. There are considerably more open spaces than for existing CLT multi-level buildings which rely on multiple shear walls.
This paper presents a study on the seismic design of hybrid multi-storey wood buildings made of CLT and Light-Frame shear walls acting at the same level. Within the framework of the force-based method, the aim of this study is to propose a simple formulation in order to establish the value of the q-factor of the hybrid system which could be also implemented in seismic design codes such as Eurocode 8. This was achieved by analysing the results of nonlinear dynamic (time-history) analyses performed on a four storey case-study building with different combinations of CLT and Light-Frame shear walls.
The cross laminated timber (CLT) technology is nowadays a well-known construction system, which that can be applied to several typologies of residential and commercial buildings. However some critical issues exist which limit the full development of the CLT construction technology: problems in handling, difficulty in assembling...
International Conference on Structures and Architecture
Structures and Architecture: Beyond their Limits
Proceedings of the Third International Conference on Structures and Architecture (ICSA2016), July 27-29, 2016, Guimaraes, Portugal
In the last twenty years CLT (cross-laminated timber) panels have become quite widely employed to build multi-storey buildings often characterized by the presence of many internal and perimeter shear walls. Building superstructures in which beam-and-column frameworks resits effects of gravity loads and core substructures and exterior CLT shear walls resist effects of lateral forces have been found structurally effective. Advantages of such structural arrangements can include creation of large interior spaces, high structural efficiency, and material economies. Here the behaviour of multi-storey buildings braced with CLT cores and additional CLT shear walls is examined based on numerical analyses. Two procedures for calibrating numerical analysis models are proposed and discussed here. The first approach is to use information from Eurocode 5, and the second approach is to use specifically applicable experimental data obrained through laboratory studies. Technically different ways of connecting CLT panels in order to obtain suitably stiff horizontal diaphragms are also presented.
This paper deals with aspects of force- and displacement-based design of multistorey cross-laminated timber (CLT) structures. A method to determine the behavior factors for timber structures based on nonlinear static analyses will be discussed. Different types of analysis models are considered. Results of experimental investigations on connections and CLT wall elements will be presented as a basis for numerical simulations.
Timber-steel hybrid beams have been proposed, tested and analyzed for their use in multi-storey buildings. After the first concepts and tests were presented in the WCTE 2014, two whole testing series are finished and their results globally presented and analyzed. The beams fulfilled all the expectations and therefore can be presented as a reliable possibility for future proposals of timber-based frame multi-storey buildings. The present paper presents a summary of the part regarding hybrid beams inside the research project “Timber based mixed systems for dense construction in urban areas” carried out by the Institute of Structural Design and Timber Engineering of the Vienna University of Technology.