Australian Life Cycle Assessment Society conference
The use of timber construction products and their environmental impacts is growing in Europe. This paper examines the LCA approach adopted in the European CEN/TC350 standards, which are expected to improve the comparability and availability of Environmental Product Declarations (EPDs). The embodied energy and carbon (EE and EC) of timber products is discussed quantitatively, with a case study of the Forte building illustrating the significance of End-of-Life (EoL) impacts. The relative importance of timber in the context of all construction materials is analysed using a new LCA tool, Butterfly. The tool calculates EE and EC at each life cycle stage, and results show that timber products are likely to account for the bulk of the EoL impacts for a typical UK domestic building.
Cross laminated timber (CLT) is a new engineered wood product that has experienced rapid growth and market acceptance for residential and non-residential construction in western and central Europe. Potential exists for rapid market adoption in North America if manufacturing capacities are developed. Dissemination of information on CLT North America markets, manufacturing capabilities, and product standards are the next key steps for facilitating investment in CLT manufacturing capacities in North America. This paper compares standards for CLT between Europe and North America.
In the 20 years since its invention in Europe, cross-laminated timber (CLT) has become a widely used construction material in parts of the old continent and has started to attract global attention. CLT possesses numerous advantages as a construction material, including its superior structural and environmental performance, as well as the speed and efficiency with which CLT buildings can be erected. In this study, European engineers were surveyed to learn about their current level of awareness of CLT, the major barriers to CLT adoption, and about the most pressing research needs to advance the use of CLT as a construction material. The study used a web-based survey with a convenience sample of 93 different kinds of timber and civil engineers and/or researchers, most of which belong to a European CLT research network. Results showed that participants think that, in general, the level of awareness about CLT among developers, construction managers, engineers, architects, and construction managers, is low. The majority of perceived barriers for CLT adoption involved its building code compatibility and the availability of technical information. The most pressing research needs for CLT development, according to respondents, are in the areas of structural performance and connections, moisture performance, and market research.
The work presented in this report is a continuation of the FPInnovations' research project on determining the performance of the CLT as a structural system under lateral loads. As currently there are no standardized methods for determining the resistance of CLT shearwalls under lateral loads, the design approaches are left at the descretion of the designers. The most common approach that is currently used in Europe and North America assumes that the resistance of CLT walls is a simple summary of the shear resistance of all connectors at the bottom of the wall. In this report some new analytical models for predicting the design (factored) resistance of CLT walls under lateral loads were developed based on connection properties. These new models were then evaluated for their consistency along with their models that are currently used in North America and in Europe.
This state-of-the-art report has been prepared within COST Action FP1402 Basis of structural timber design from research to standards, Working Group 3 Connections. The Action was established to create an expert network that is able to develop and establish the specific information needed for standardization committee decisions. Its main objective is to overcome the gap between broadly available scientific results and the specific information needed by standardization committees. This necessitates an expert network that links practice with research, i.e. technological developments with scientific background. COST presents the ideal basis to foster this type of joint effort. Chapter 8 Connections presents an integral part of Eurocode 5 and is in need of revision. This state-of-the-art report shall provide code writers with background information necessary for the development of the so-called Second Generation of the Eurocodes, now aimed to be produced in 2022.
This paper presents energy and environmental performance analyses, a study of summer indoor temperatures and occupant behavior for an eight story apartment building, with the goal to combine high energy efficiency with low environmental impact, at a reasonable cost. Southern Portvakten building is built with prefabricated timber elements using passive house principles in the North European climate. Energy performance was analyzed through parametric studies, as well as monitored energy data, and complemented with analysis of occupant behavior during one year. Results show that airtight, low-energy apartment buildings can be successfully built with prefabricated timber elements in a cold climate. The monitored total energy use was 47.6 kWh/m2, excluding household electricity (revised to a normal year), which is considerably lower than of a standard building built today in Sweden—90 kWh/m2. However, the occupancy level was low during the analyzed year, which affects the energy use compared to if the building had been fully occupied. Environmental analysis shows that the future challenges lie in lowering the household and common electricity use, as well as in improving the choices of materials. More focus should also lie on improving occupant behavior and finding smart solar shading solutions for apartment buildings.
The report has segmented the European CLT market on the basis of application. Some of the key application areas of CLT include educational institutes, residential, commercial spaces, and government and public buildings. On a regional basis, the report has segmented the market into Austria, Germany, Italy, Switzerland, Czech Republic, Spain, Norway, Sweden, United Kingdom and Others. Amongst these, Austria represents the largest producer accounting for the majority of the total production. Apart from the application sector and region, the European CLT market has also been segment on the basis of product type, element type, raw material type, bonding method, panel layers, adhesive type, press type, storey class and application type. The report provides historical as well as forecast trends for each of the above market segmentations. The report has also analysed the competitive landscape of the market with some of the key players being Binderholz, Stora Enso, KLH Massivholz, Mayr Melnhof and Hasslacher.
The objective of this work package is to provide an acoustic performance knowledge database of European timber building constructions. In a first step a methodology for structuring the planned data base will be developed. The database will be fed with existing examples from the different European timber building regions. These examples will be grouped into similar solutions and sound insulation performance. After reprocessing the data the different construction systems will be optimized in WP 2.
An interface to the borad public of the database will then be developed. This user friendly and appealing front-end of the European Timber Sound Insulation Atlas (EATSI-Atlas) will provide information on various evaluation criteria, including expected future European target values.
This paper presents an experimental study on rolling shear (RS) strength properties of non-edge-glued cross-laminated timber (CLT) made out of New Zealand Radiata pine (Pinus radiata) structural timber. CLT specimens with 35 and 20 mm thick laminations were studied to evaluate the influence of lamination thickness on the RS strength of CLT. Short-span three-point bending tests were used to introduce high RS stresses in cross layers of CLT specimens and facilitate the RS failure mechanism. Modified planar shear tests from the conventional two-plate planar shear tests were also used to evaluate the RS strength properties. It was found that two test methods yielded comparable RS strength properties and the lamination thickness significantly affected RS strength of the CLT specimens. The test results also indicated that the recommended characteristic RS strength values of CLT products in Europe and Canada might be over conservative. Also, it might be more efficient to specify different RS strength values for CLT with different lamination thickness given the minimum width-to-depth ratio of laminations is satisfied.