Conferences and workshops abstracts
Influence of public policy on wood development in mid-rise and high-rise buildings
Emmanuel Acchiardi – Direction de l’Habitat, de l’Urbanisme et des Paysages (DHUP)
Compte tenu des performances « carbone » du bois, de ses caractéristiques énergétiques et environnementales, et de son potentiel de valorisation de la ressource nationale, le développement du bois dans la construction et la réhabilitation des bâtiments est un axe affirmé des politiques publiques conduites par l’État.
En 2013 la filière bois a été désignée « filière d’avenir pour la compétitivité de l’industrie française » et dotée d’un comité stratégique de filière en 2014 intégrant pouvoirs publics et professionnels.
La DHUP travaille activement à l’évolution des mesures législatives et réglementaires, en particulier en matière d’urbanisme pour favoriser le recours à la construction bois. En complément d’un soutien actif dans les territoires au travers de son réseau des DREAL, la DHUP accompagne la filière bois depuis 2009 avec des plans d’actions inscrits dans le contrat de filière. Les plans Bois font l’objet d’une collaboration forte entre les professionnels et l’État pour développer des outils au service de l’utilisation du bois dans la construction, les objectifs étant d’identifier et de surmonter des freins culturels, réglementaires, normatifs et techniques.
ADIVbois: a dynamic to carry the National Wood Industries Plan
Frank Mathis, ADIVbois
Impulsé par les Pouvoirs Publics, développé par un ensemble de professionnels impliqués et fondé sur un principe de partage permanent, le Plan Industries du Bois repose sur un projet très concret : les Immeubles à Vivre Bois. Ces immeubles innovants mixent verticalité bois et nouvelle approche du cadre de vie, mêlant architecture et design, pour apporter une réponse efficace et pérenne à la Ville Durable.
Porté par l’Association pour le Développement des Immeubles à Vivre Bois, ce projet déploie les outils et solutions nécessaires à la réalisation d’immeubles prototypes. Une dynamique d’open source est appliquée au projet d’Immeubles à Vivre Bois afin d’accompagner, de faciliter et d’accélérer le développement de ces premiers immeubles. Aujourd’hui, 24 projets sont lancés. Le 12 septembre, les premières équipes qui concevront et réaliseront ces nouveaux immeubles seront dévoilées. Un nouveau chapitre s’ouvre et la dynamique de partage se poursuit pour faire grandir la construction bois en France.
Promotion of wood in the urban planning of the City of Yokohama, “the Future Eco City
Kenji Hosaka, Direction du Bureau du Logement et de la Construction de la ville de Yokohama, Japon
Yokohama city has been developed as an international gate way in Japan since 1859 in Edo period.
Yokohama city is the largest municipality with a population of 3.7 million people, facing major challenges such as rapid aging population and energy problems associated with the Great East Japan Earthquake that occurred in March 2011.
Under these circumstances, Yokohama city has been selected as « Environment Futuristic City » by the government, and along with the revitalization of the economy, Yokohama city is addressing urban issues such as responding to an aging society and reducing CO2 emissions.
In addition, Yokohama city is promoting a lifestyle with less energy consumption, the wood as a renewable resource, and less CO2 emissions during construction and manufacturing.
During Woodrise congress, Yokohama city will introduce how the usage of wood is stimulated in different areas: « low-carbon town planning », « promotion of energy efficient houses and buildings », « collaboration with businesses and universities », « usage of wood in public buildings”.
Interest of the Wood Material in Terms of Comfort and Well-Being in a Building
Koichiro Hirata, Nice Holdings, Japon
The Hirata Family, the founders of Nice Corporation, has been involved in the timber business in Yokohama since the 18th century and established the corporation in 1950. Koichiro Hirata, the current president, is the 10th generation president.
Handling more than 1 million cubic meters of timber annually, the current Nice Corporation sells construction materials and housing equipment to construction companies and also supplies wooden housing and wood constructed buildings in Japan, France, Belgium, America, and Indonesia.
Japan has been developing its culture together with trees as typified by the pit-dwellings of the Jomon Period in the 4th century BC and by Horyuji Temple, the world’s oldest wood constructed building erected in the 7th century.
At one time in Japan, there were many “bald” mountains and trees were precious, but the government has succeeded in developing man-made forests after World War II. The current accumulation of forests is 4.9 billion cubic meters including the softwood of cedar and cypress, and Japan’s forest ratio is 68.5%, the second largest among developed countries.
Since the past in Japan, the fragrance, texture, and substances emitted from wood have been regarded as good for the mind and body, and recently, various kinds of scientific research on the benefits of wood are being conducted by government agencies such as the Forestry Agency and academic institutions.
In a business, government, and academic collaboration with Yokohama City and Keio University, we began the establishment of a facility to experience and feel the sensation of factors related to home living and health called Smart Wellness Experience Pavilion in 2015. At the facility, demonstration experiments are conducted regarding the benefits of wood such as the improvement of intellectual productivity due to the change to wood use in the interior, and the facility contributes to the collection of data concerning the relationship between health and home living.
In the future, Nice Corporation will continue to work on improving the quality of life of people in a sustainable society, shedding light on the benefits of wood, and expanding the use of timber.
Public Policy and Tall Wood Buildings in Canada
Robert Jones – Natural Resources Canada
Addressing climate change is one of the top priorities of the Government of Canada. Natural Resources Canada, (NRCan) and provincial/territorial governments see increased wood use in the built environment as one means of providing high climate mitigation opportunities while improving the energy efficiency of most buildings. NRCan has recently launched a multi-year initiative to support demonstration projects and activities that increase the use of wood as a greener substitute material in infrastructure projects. The initiative, building on earlier Government of Canada investment to encourage greater use of wood in domestic construction, will support building code changes and the construction of tall wood buildings. By accelerating the adoption of wood use in structural applications to reduce energy usage and emit fewer greenhouse gas emissions (GHGs), the initiative will contribute to supporting Canada’s long-term low GHG development strategy.
Implementing strategies to encourage the construction of tall wood buildings
Etienne Lalonde – Canadian Wood Council
Interest in constructing tall wood buildings in Canada is gaining momentum. Over the past few years, numerous advocacy, educational and promotional strategies have been developed and implemented by a national network of partners to encourage the construction of tall wood structures. Special initiatives such as the Tall Wood Demonstration Program, educational workshops and international symposiums and the development and distribution of communication pieces including case studies, tall wood technical guides, and trade journal and magazine articles have helped to accelerate the acceptance of wood as a suitable structural material for high-rise construction. Working closely with government, industry and research agencies, the CWC and its Wood WORKS! program continue to advocate for the expanded use of wood and hybrid structural solutions and lead the charge to demonstrate why the National Building Code of Canada should accept wood in structures of up to 12 storey in heights by 2020.
Introduction conference : Multi-disciplinary approach in the design and construction of tall wood buildings
Erol Karacabeyli, FPInnovations, Canada
Construction of tall wood buildings is not a new phenomenon. In the beginning of the 20th century, buildings as high as 9 storeys were constructed with large or ‘heavy’ solid sawn timbers. Many of those buildings are still serving their owners. Towards the mid-20th century, that system however, was replaced by reinforced concrete and steel systems in tall buildings and from thereon wood buildings (mostly light frame) continued to be built in one to four story category.
Leaders or “early adopters” within the design and construction community who see the environmental and aesthetic benefits of building with wood recognize the new opportunities made possible by modern mass timber products and systems. Relying on the knowledge created by applied research, they are willing to take on the challenge of building tall wood buildings in advance of formal recognition in building codes. Building with this class of large modern wood members is called ‘mass timber construction’ and includes products such as glued-laminated timber (glulam), structural composite lumber (SCL) and cross laminated timber (CLT). The interest from these early adopters triggered government/industry led initiatives in several countries to support tall wood building demonstration projects showcasing the application and performance of those advanced wood technologies.
As part of one of those initiatives, FPInnovations has released the first edition of the Technical Guide for the Design and Construction of Tall Wood Buildings in Canada. Recognizing the challenge of building a structure that is not formally recognized in the building code highlighted the need to take a multi-disciplinary approach to developing technical guidance to support the design and construction of tall wood buildings and to facilitate acceptance by local authorities or “Authorities Having Jurisdiction” using the alternative solutions path in building codes. The Guide was developed under the guidance of a working group of more than 80 technical professionals comprising design consultants and experts from FPInnovations, National Research Council and the Canadian Wood Council. Through this working group, the areas requiring guidance were identified and the best available technical information was assembled from various sources. The Guide then underwent review by North American as well as overseas experts.
Design teams of tall wooden buildings will have specific design, construction, and maintenance challenges that will need to be addressed. In many instances, design solutions for satisfying the demands from a particular performance attribute create additional challenges for satisfying another performance attribute (for example design solutions for better sound performance at times negatively affect the structural performance). This Technical Guide is designed to systematically address those challenges. Intended to assist architects, engineers, building officials, developers, owners, and Authorities Having Jurisdiction (AHJ), the Guide is not specific to any one structural solution. Rather, it establishes the parameters and resources necessary for a capable team to design a tall wood building that meets the performance requirements of current building codes and the competitive building marketplace.
Multi-disciplinary design approach increases the likelihoods of satisfying numerous performance demands in a balanced way.
Hybrid solutions for high rise wooden structures
Johan Åhlén, Moelven Töreboda AB
Over the past 10 years we have seen how tall wood structures have increased in numbers. However, steel and concrete structures are still dominant in terms of market share.
In Sweden only 10% of all residential buildings are made of wood. A design- and climate clever way of changing this in favor of wood is to design structures that very much assimilates how steel and concrete structures is normally designed in terms of its statical structure. By doing so, the material properties of wood is fully utilized, we don’t need to use more material than necessary and we build smart houses. This approach includes gentle usage of both steel and concrete in specific parts of the structures, such as elevator shafts as one example, creating very material efficient hybrid structures. Moelven Töreboda in Sweden and Moelven Limtre in Norway, two sister companies within the Moelven Goup shares over 150 years experience in glulam production. Over the past 10 years lots of fine examples of this approach has been realized by the two companies.
In this presentation you will be given an introduction to the « hybrid approach » for the projects Mjøstårnet and Frostaliden. One very tall (80 m) and slender iconic project and one more commercially fine tuned residential building in 8 stories.
From the first to the forefront: Waugh Thistleton’s journey from the world’s first timber tower to the disruption of construction
Andrew Waugh, Waugh & Thistleton Architects, Angleterre
Waugh Thistleton are an Architects practice based in Shoreditch East London.
In 2003 we built the first cross laminated timber building in London. This small project was the beginning of our research into how to build and design buildings which minimise their impact on the environment. Reducing the energy use of a building is fundamental but alongside this should
be an understanding of the implications of the building materials that we use.
We built this little CLT building in South London– three stories and 45sqm – on a sunny Saturday afternoon and we fell in love with this technology. What we discovered was not only a low carbon method of construction but a fast, efficient and accurate means of construction. It also made a great building – a robust and beautiful piece of architecture; and a building that had high acoustic and thermal performance.
From the foundation that this small building gave us we began to think about how this material could be used in larger buildings. The responsibility of our generation of architects is two-fold.
We have to manage a massive shift from the country to the city – a global process of urbanisation that has resulted in housing shortages in every major city. And we have the consequences of a hundred years of over using our planets resources which has led to climate change and imminent shortages of essential commodities such as sand and water.
In 2008 we embarked on our project in Murray Grove, London. The proposal was to produce a building that embodied both ideas of urban densification and low impact methods of construction. This is a high density residential building for both private and social housing that contains apartments of one, two, three and four bedrooms. The entire structure of this building from the first-floor slab up is constructed from cross laminated timber. The timber forms the floor slabs, the core structure and both principle internal walls and all external walls.
Before Murray Grove the use of CLT had been primarily with single family houses, small apartment buildings and schools. We proposed a new way of building – Murray Grove or Stadthaus as it became known was the first tall building in timber and has given rise to a new generation of timber architecture. This project also suggested a new way of considering the impact of construction on the environment – as part of our proposal we calculated the embodied carbon of our timber building in comparison to a concrete and steel building. This demonstrated that the carbon saved by building in timber was equivalent to over a hundred years of Carbon emissions needed to power the building. We had demonstrated that building in timber was a truly viable alternative to building from concrete and steel.
In 2012 having completed another seven CLT buildings we began work on our Dalston Lane project. This building represents the next development for mass timber construction in high density urban housing. The building is 16,000sqm and ten stories tall. It houses 121 apartments and 4,000sqm of work space. At the time of construction, it is the single largest built project in cross laminated timber. This volume produced its own challenges including delivery, programme and erection. However, if timber is to become the major construction material of the 21st century – as it must do – then this scale of construction is just the beginning. We have to look at mass housing for high density cities – these buildings don’t need to be the tallest in the world, but the best for our planet.
Projet Origine, bâtiment en bois de 13 étages à Québec, Canada
André Huot et Simon Gallagher, Nordic Structures, Canada
Durant les dernières années, nous avons vu une évolution de la construction de bois à grandes hauteur avec des projets incluant entre autre Wenlocke à Londres, Treet en Norvège, et Brock Commons à Vancouver. La construction du bâtiment Origine, un édifice de 12 étages conçut entièrement en bois massif sur un podium d’un étage en béton, sera habité en début MOIS.
Avant 2016, la régie du bâtiment du Québec (RBQ) ne permettait pas de bâtiment de plus de 6 étages en bois massif. Un long processus débutant en 2013, adressant les problèmes techniques relier à l’ingénierie, la protection incendie, ainsi que ___ auprès du publique c’est terminer en 2015 avec la publication des « Directives et guide explicatif pour la construction massive en bois d’au plus 12 étages » par la RQQ.
En parallèle, des essaie sur les propriétés structural du CLT et lamelle coller ont eu lieu. Développement de nouveaux détails d’assemblages.
Creativity and inspiration: integration of wood in building design
Shinri Kishishita, Kishishita Workshop, Japan
Wood has been in used in traditional Japanese architecture since ancient times which provide a great source of inspiration for modern building design. The design of the JST Corporation headquarters building in Osaka, Japan, draws upon the knowledge of traditional Japanese architecture whereby comfortable work space is created by integrating wood interior and exterior of the office building. The wood used is from domestic origin. The usage of wood in the design of large-scale buildings will become more important than before.
Increased integration of wood in both the interior and exterior design of office spaces has positive effects on the creativity of the office workers and inspire them more.
Hyperion Tower, Bordeaux
Jean-paul Viguier, Jean-Paul Viguier et Associés, France et Jacques Bouillot, Eiffage Construction, France
Le projet Hyperion, dont le PC vient d’être déposé en vue d’une commercialisation rapide, culminera à 57 mètres de haut. Ce bâtiment entre dans le segment supérieur des tours de moyenne hauteur puisque le plancher bas du dernier appartement se situe à 50m (famille 4).
L’équipe de conception, coordonnée par Eiffage Immobilier (maître d’ouvrage) et Eiffage construction (entreprise générale), comprend le cabinet d’architecture Viguier, le bureau d’étude structure Terrel, Woodeum agissant en tant que partenaire, Aïda pour l’acoustique, Vulcaneo et Efectis pour l’ingénierie de la sécurité incendie, cetab pour les fluides/HQE. Elle a travaillé à marche forcée pour mettre au point ce bâtiment emblématique et complexe.
Socotec est le bureau de contrôle de cette opération. A ce titre l’échange tripartite entre leurs équipes, l’équipe de conception de Hypérion et les équipes du CSTB-FCBA a été essentiel dans l’aboutissement d’une solution globale et cohérente.
L’ADEME accompagne ce projet pour le caractère exemplaire et reproductible des deux solutions techniques apportées au monde du bois.
En effet, Hypérion résout principalement deux problématiques :
– L’une concerne les façades en mur ossature bois posées en manteau sur structure bois en famille 4. L’ATEX en cours offrira l’ouverture de nouveaux marchés pour les ossaturistes dans le cadre du label E+C- à venir.
– L’autre traite le sujet des balcons en console en proposant des solutions de façades proches de celles employées traditionnellement. Cette application vaut en particulier pour les bâtiments de la famille 3 (<28m) qui est le segment de marché le plus significatif en volume visé par Adivbois. De plus, le projet Hypérion véhicule également une philosophie que l’on pourrait résumer de la façon suivante : Le bon matériau au bon endroit. Le projet Hypérion participera sans nul doute au développement économique de la filière bois en Nouvelle Aquitaine puisque le bois y est majoritairement représenté en s’appuyant sur les lamellistes, ossaturistes et producteurs de CLT. Pour autant, l’équipe de conception, n’a pas cédé au dogme du tout bois, et n’a pas hésité à mixer les matériaux au profit d’un optimum technique et prix en vue de garantir le caractère reproductible de l’ouvrage. Cela faisait partie de la mission que nous avait confiée Euratlantique lorsqu’elle a désigné le groupe Eiffage et ses partenaires, lauréat de l’îlot 8.4
Increments of change : from early Tall Wood Buildings to a global movement and Timber Online Education Program
Michael Green, Michael Green Architecture, Canada
SYSTEMIC CHANGE IN THE WAY WE BUILD OUR CITIES
We stand at the edge of a systemic shift in the way we build and the way we live. As the world searches for ways to address environmental and climate issues, we have come to realize that living more densely is fundamental to the future of mankind and to our relationship with our planet.
For a century and a half, steel and concrete have shaped the skylines of the world. They are wonderful materials that allow big buildings, bridges, and roads but we now also know that they are hugely energy demanding materials to produce, with significant carbon footprints. Today we
understand how dramatically our climate is changing and we know that the future of society will be severely impacted. We also know that as world populations grow and people move into cities at an increasing rate that we will need to continue to build housing and infrastructure to support
Climate change and the need for more urban housing collide in a crisis that demands building solutions with low energy and low carbon footprints. Wood, unlike steel and concrete, sequesters carbon dioxide, storing it away for the life of the building it is in. As a renewable
material, wood offers us a new way to think about our future. To do so it means reinventing wood; making it stronger, more fire safe, more durable, and selecting material from sustainably managed forests.
Wood is the only major building material we can build with that is grown by the sun. Its strength to weight is phenomenal and man-made energy is only used to handle it and move it to site. One cubic metre of wood stores 1 tonne of carbon dioxide. The only way we address anthropogenic
climate change is by storing carbon and reducing our emissions. Wood does both. Over the last decade a new conversation about sustainable cities and climate change has questioned the methods of the past and through a host of innovators and global voices for change, we have seen a new revolution of tall wood buildings proposed around the world.
Advantages of wood design include:
• Lower embodied energy
• Lower operating energy (when appropriately designed)
• Pre-fabricated design, for ease and precision of construction
• Reuse at end of life
• Environmental impact indicators:
o Carbon sink
o Reduced GHG emissions
o Reduced air/water pollution
TIMBER ONLINE EDUCATION
The world faces an existential climate and population crisis. New and affordable housing is
needed to accommodate growing urban populations worldwide. Today our built environment
contributes more than a third of our energy use and carbon emissions. There is a persistent lack of
jobs and shortage of skilled labour in the construction, manufacturing, and rural industries that
cannot keep up with demand. We need a solution that can reconcile these complex,
interconnected issues by creating a shared resource for education and innovation in the built
Currently there are a limited number of professionals and teachers around the world who are
experienced in this new model of construction. The interest in these buildings is growing quickly
but an uninformed industry will risk mistakes that can cost lives or cause unintended
TOE is the solution.
TOE | Timber Online Education is an online education program initiated with the aim of building a
global resource of wood design, construction, business, sustainability knowledge and expertise
for a new generation. TOE will offer educational programs with a broader and deeper curriculum
to cover all levels and aspects of wood construction and building, guided by the leading experts
of the industry.
A Urban Developer gets involved in the Wood Construction Industry
Jean-Baptiste Rey , EPA Marne-la-Vallée, France
Et si l’avenir du bois c’était Marne-la-Vallée ?
Ne voici pas que le matériau par excellence de la construction, utilisé de temps immémoriaux, retrouve sa place et voit, à nouveau, sa valeur reconnue ? Les qualités thermiques du bois, sa facilité d’utilisation, son coût de revient et, par-dessus tout, ses propriétés écologiques en font aujourd’hui le matériau de la modernité.
L’enjeu pour Marne-la-Vallée a été de faire de ce choix économique et écologique un choix pérenne. Nous avons souhaité qu’une véritable filière puisse se structurer, et garantissons un volume de production. Simultanément, nous explorons quelques exemples de pointe. Pour que le TGV puisse rouler couramment à 320 km/h, il faut l’avoir testé à 515. C’est bien ce que nous faisons avec des opérateurs audacieux, et avec le soutien du FCBA et du CSTB.
Sur les deux dernières années, Epamarne a lancé plus de 1 800 logements en bois et il y en a partout sur le territoire de Marne-la-Vallée. De Bry à Magny, en passant par Noisiel avec le beau projet du Crédit Agricole Immobilier. Avec Vinci Construction, nous avons mis au point un projet très innovant, le premier parking à deux niveaux en bois. Derrière un petit parking de 100 places de stationnement, c’est tout le marché des entrepôts à étages qui s’ouvre au bois. Avec Expansiel à Chanteloup, nous avons développé les premiers logements en bois, neutres sur le plan carbone pendant toute leur vie. Pour aller plus loin encore, nous voudrions tester un immeuble de logements, nommé « Bois 22 » pour XXIIème siècle. Sans moyen mécanique, cet immeuble en bois garantira un bon confort d’été. Et serait toujours à même de le faire en 2117, 2217… alors que le climat aura évolué.
Le bois nous permet cette démarche d’imaginer un immeuble qui soit aussi agréable pour nous que pour nos arrières petits-enfants, et cela avec très peu de moyens mécaniques, seulement par ses qualités propres et la ventilation.
En 2017, la moitié de notre production, et peut-être davantage, sera encore lancée en bois. L’avenir de la construction à Marne-la-Vallée passe par le bois.
Sotramont – Construction of two CLT residential projects simultaneously – including the world’s largest Arbora
Marc-André Roy, SOTRAMONT, Canada
La perspective unique du développeur et constructeur de 2e génération, Sotramont.
• Les leçons tirées de la construction en simultané de 2 projets multi-résidentiels en CLT (Cross Laminated Timber), dont l’un est le plus vaste projet d’habitation doté de cette structure en bois massif, au monde.
• Comment Sotramont a adopté le développement immobilier certifié LEED® et sa vocation au développement durable.
• Aperçus sur son savoir-faire relatif au marketing et à la vente de projets CLT auprès des joueurs clés de l’industrie et des consommateurs immobiliers résidentiels.
A unique perspective from 2nd generation developer and builder Sotramont.
• Lessons from simultaneously constructing 2 multi-residential CLT (Cross Laminated Timber), projects, including the world’s largest residential project with an entirely CLT structure.
• How Sotramont adopts LEED® certified development.
• Insights on marketing and selling CLT to development influencers and residential consumers.
Trees : nature’s 3D printers
Steven Ware, Art and Build, Belgique
L’outil numérique défie et impacte le monde du bâtiment. BIM, big data, impression numérique… Cette impression est au cœur des questions fondamentales de notre cabinet. A quoi ressemblera l’imprimante idéale pour produire des éléments de construction de demain ? Évidemment, elle se nourrira d’énergie solaire. Par son activité elle piégera le carbone de l’atmosphère. Elle extraira la matière première de nos sols mêmes. Elle proposera à chaque sol une impression adaptée. Et elle sera d’autant plus performante si ce sol contient certains déchets organiques. Les matériaux qu’elle produira seront résilients aux insectes, parfois parfumés, parfois comestibles. Résiliente aussi aux aléas de nos saisons – vent, humidité – elle n’aura besoin ni de hangar ni d’abri. Et plus important encore, elle hébergera la biodiversité, entrera en symbiose avec d’autres espèces, produira de l’oxygène et, pourquoi pas, saura se reproduire.
Cette immense gamme d’imprimantes au service du bâtiment porte un nom : l’arbre.
Us market update and perspective for tall wood projects
Jennifer Cover, WoodWorks, Etats-Unis
As examples of successful tall wood buildings proliferate worldwide, many U.S. architects are seeking to leverage wood’s sustainability and other advantages through their own tall wood building designs. This presentation will examine the current landscape for tall wood buildings in the U.S., including building codes and market opportunities, potential benefits in terms of job creation and forest health, and efforts by the U.S. Department of Agriculture, U.S. Forest Service and the wood industry to support these innovative structures. Designers understand that pursuing ambitious carbon reduction through the use of wood is only viable if they can also achieve a high degree of life safety and building performance, and this presentation will cover efforts to update building codes to reflect this new design approach. It will also consider two tall wood projects going to construction this year, and the research supporting their approval through the Alternate Methods & Materials code path. Other topics will include efforts to strengthen markets for wood that are, in turn, leading to more resilient rural economies and increased opportunities for landscape restoration.
Mass Timber and Hybrid Construction in Mid to High Rise Developments – Cost and Performance Values
Nick Milestone, BK Structures, Singapour
In the last 15 years, the use of Structural Timber in the United Kingdom has seen a dramatic increase in use across all market sectors, from early use in leisure industry through to retail, education, and commercial office and now seen as the most effective structural solution for the mid-high rise residential sector.
The use of mass timber (Glulam and Cross Laminated Timber) has proven to be versatile combined with other structural materials such as concrete but more effectively combined with structural steelwork can offer a viable and cost effective structural solution.
Due to the recent advancements in BIM (Building Information Modelling) Mass Timber has now found its way into the supply chain providing light weight and sustainable solutions in the DfMA (Design for Manufacture and Assembly) market especially where there is a high demand for Off-Site manufactured components for use in both the ‘2D flat pack’ and ‘3D volumetric’ market.
As both labour and raw material prices increase in concrete, due to is lightweight nature and added value of speed in construction, Mass Timber is now proven to 10% cheaper and 20% quicker than the traditional use of reinforced concrete frame buildings.
Mass Timber is the only construction material that offers a true proposition toward the circular economy, utilizing a material that not only a natural carbon sink but it is grown for construction purposes, with the enhanced offering of a ‘Pre-Manufactured Value’ above other traditional forms of construction.
Advances in knowledge gained from lessons learned in constructing some 300 Mass Timber buildings in the UK has led to several key documents being produced from within the UK construction Industry offering guidance on the use of Mass Timber in all building applications from established associations.
The age of the forests
Kengo Kuma, Kengo Kuma & Associates, Japan
Forests in Japan
In the past, architecture was part of the forest in Japan. Both of these elements existed as an integral part of a circulating system. When trees in the forest near homes grew to a certain size, they were cut down and used as the materials to build and repair homes. These materials consisted of timber with a length of around 3 meters and thickness of around 10cm, which was used to build almost all structures in cities in Japan.
If a computer term is used express the system in Japan, I think that this lumber could be called the operating system, or OS. On the other hand, the OS in Europe was stone and bricks. When buildings are made with an OS that consists of stone and bricks, they tend to foster a dichotomy-like style of thinking in society in which there is a clear differentiation between the inside and outside or allies and foes due to the fact that there is a very clear boundary between the inside and the outside. In contrast, in cities in Japan where buildings were made by assembling frames using thin pieces of lumber, since it was more difficult to close off the inside from the outside, it resulted in the creation of open and ambiguous space where the inside and outside became integral, and I think that this led to a tendency to think of things in an ambiguous manner that is adaptable.
Since wood is warm and soft to the touch, homes built using wood have nurtured a sense in people of perceiving the environment around them as extension of the body and a peer, rather than perceiving the body as being in confrontation with buildings.
The foremost difference between these two operating systems (OS) is the method in which time is processed. Since it takes a lot of time and trouble to tear down or repair architecture built using stone once it has been completed, people tend to think that architecture and cities are permanent and you cannot go back on once it has been completed. On the other hand, it is easy to add to or change buildings made using wood in Japan, which means that you can go back and change things afterwards, and even freely change the location of pillars in some cases. The ability to make changes afterwards nurtures a soft philosophy of time in which things can be flexibly manipulated.
I think that this philosophy of time as well as the human scale of gentleness and warmth unique to materials represent a great treasure for the culture of Japan and are the core of Japanese culture.
However, the importation of concrete in the 20th century completely changed Japan. The reason for this is that it is even colder and harder than stone or brick, is very difficult to tear down or repair, and has a character which is the antithesis of soft and warm wood, which can be called a super Western OS. Cities in Japan were almost completely rebuilt with this new OS, and the forests in Japan were decimated. I think that the time has come at which we must seriously examine what this has done to the culture and spirit of Japan.
Session: Forest resources and wood products for mid-rise and high-rise buildings: experiences
How do the European Sawmill Industries integrate the Second Transformation Process Needs into their Planning and Strategies?
Carsten Doehring, EOS Europe
ILIM TIMBER -WHO WE ARE. Ilim Timber is one of the leading suppliers of softwood. Headquartered in St. Petersburg, Russia, its production facilities are located in Siberia and in Southern and Northern Germany. The company with sales offices in the EU and in China, has a unique global production and distribution platform with strong presence on all major softwood sawn timber markets including Europe, MENA, US and Asia. The company supplies Angara Pine, Siberian Larch, Bavarian spruce as well as Norway Spruce and Nordic Pine as main species. The total annual capacity amounts to 2 650 000 m3 of sawn timber and 220 000 m3 of plywood. The total headcount of the company is about 3000 people, mainly in Russia.
GENERAL OVERVIEW. The presentation reviews -in particular- the European sawn timber market and the correlated demand of wood products. It opens with a general introduction of the softwood sawn production and consumption in Europe. From the data, it is evident that the sawn softwood production across European Countries is rising at a moderate but steady pace, with growth driven mainly by buoyant export markets in Asia and again the US. Sawn hardwood production is overall stable in spite of raw material availability challenges, particularly in large producer countries, such as France, Germany and Romania.
TRADITIONAL TIMBER CONSTRUCTION AND SAWMILL OPERATION. The building sector for centuries has been the main customer for sawn timber – be it residential or non-residential. In the European tradition, timber construction required local and made-to-order production. In this respect, the sawmills represent the first transformation process.
MEGATRENDS IN CONSTRUCTION AND THEIR EFFECTS ON SAWMILLS. During the last decades, timber construction in Europe is undergoing dramatic changes:
1 The standardisation and modularisation of buildings and new design methods require standardized engineered-wood products, tailored to customer needs and in consistent quality. The growing urbanisation requires a higher degree of pre-fabrication that guarantees shorter construction times, a more meticulous planning process and quality assurance of the production system. The use of engineered wood products has driven down costs, improved performance and extended the applications of wood construction. Modular construction stands for “High quality, sustainable, innovative, efficient, cost-effective, and shorter time to completion”. Wood is now recognized for its unique properties: the structure of strengths, weight and insolation.
Sawmills have answered those trends either through integration of second processing facilities or by specialising in large scale manufacturing facilities. Achieving sustained profitability in sawmilling hinges on system-wide process optimization. Consequently, sawmill companies around the world are looking to invest in advanced technologies across a range of areas, from log handling right through to timber drying, optimization and packaging. Technologies for determining round wood and lumber dimensions and quality (as the X-ray scanners) are another important means of answering today’s requirement in sawmilling.
2 The construction industry is facing a transformation time as National Governments are looking for increasing the use of eco-friendly materials and alternatives to more sustainable buildings. In the EU-28, about 70% of the population lives in urban areas, and this share is expected to further increase in the future. It is thus essential to create an urban development that is both economically and environmentally sustainable. In this prospective, sawn products lead the way in green building materials.
MARKET FORCES AND SAWMILL ANSWERS. China is the world’s largest construction market and will continue to provide strong opportunity for the European Sawmill Industry. Increasing urbanization and the national commitments to reduce greenhouse gas emissions drive China’s steady commitment to expand the use of green products such wood. The uses of wood in construction can have different application: supporting structures (including framing) facades (panels, cladding), exterior joinery, joinery and interiors, flooring and walls (parquet, panelling).
Looking into another important market -the USA- it is undeniable that building construction – especially residential construction – accounts for nearly one half of the lumber consumed in the United States. Therefore, housing starts are one of the most reliable predictors of lumber sales in the US. After 8 years of growth following the decline observed in the aftermath of the global economic crisis, housing starts have slowed down in the Spring 2017. Economic fundamentals remain strong, and according to Bloomberg, this may represent a blip rather than the beginning of a downward trend.
We expect the worldwide demand for sawn timber to continue to grow; European forests are a sustainable source.
CONSIDERATIONS. Action aiming at promoting wood in construction (both at European and International level) as part of the climate change policy (e.g. slowing down global warming) can have a positive effect on the competitiveness of the sawmill companies and facilitate the sawn products trade.
Hopefully, the use of wood usage will continue to grow, particularly in construction applications, as more people appreciate wood’s environmental properties and excellent structural performance. Additionally, because sawmills are often located in rural area choosing wood means supporting rural development and green jobs.
Highlighting different species within the same CLT production: challenges and feedback
Nicolas Gentner, Schilliger Holz AG, Switzerland
L’entreprise Schilliger valorise ses bois sciés dans la seconde transformation en produisant du bois abouté, du lamellé-collé ou du CLT. L’exploitation de bois locaux et la maîtrise de l’ensemble du process de fabrication permettent de fournir des composants de haute qualité, d’en réduire l’impact environnemental final et de proposer des produits innovants tout en restant compétitif.
En particulier, la production de CLT représente une véritable valeur ajoutée depuis la grume jusqu’à la livraison des panneaux taillés. Tous les panneaux sont produits à la demande : les dimensions, les essences et le degré de qualité esthétique sont choisis par le client. La diversité des demandes nécessite une maîtrise du process et un suivi qualité quotidien, donc une grande flexibilité à toutes les étapes : approvisionnement constant des différentes essences, stockage des grumes, sciage, séchage, aboutage, rabotage, collage, optimisation esthétique, ponçage, taille, stockage et chargement, mais aussi dans la planification et l’ingénierie.
Cette fabrication sur mesure apporte une solution précise aux besoins du client et répond aux projets les plus exigeants.
Current situation of forestry and efforts to CLT in Japan
Koichiro Nakashima, Meiken Lamwood Corporation, Japan
Despite using up its forest resources in war, Japan has now recovered its forests as a result of post-war afforestation policies implemented in the 1950s.
On the other hand, harvest efficiency and material productivity is low compared to Europe, partly due to the long period of protection-oriented policies focused on forest maintenance.
Industry, academia and government have been cooperatively involved in CLT since around 2010.
The government is keen on promoting CLT, and plays a key role in drawing up material standards and building codes: creating demands for unutilized forest resources and enhancement of rural economies through forestry are some of the motives behind.
MEIKEN has been leading the development of CLT in Japan from the very beginning, notably establishing the Japan CLT Association in 2012 and running the first Japanese mass-production CLT factory from 2016.
Characteristics of the CLT situation in Japan:
A) Rules first: standards and codes have preceded commercialization and actual demands
B) High physical requirements for buildings due to earthquakes
C) Possibility to utilize the existing pre-cut (CNC processing) infrastructure nurtured by the Japanese post & beam housing market
D) Entry from other fields and collaboration with other markets (currently) scarcely observed
Black Spruce Leading to New Heights
Simon Adnet et Florian Lagarde, Les chantiers Chibougamau, Canada
La construction bois au Québec, au Canada et plus globalement en Amérique du Nord, connaît depuis plusieurs années une réelle transformation, se traduisant par une augmentation significative des parts de marché dans les secteurs non résidentiels et résidentiels de moyenne et grande hauteur.
Les différentes politiques publiques, l’émergence de nouveaux produits et modes de construction ainsi que l’évolution des codes de construction ont accéléré cette croissance, positionnant le bois comme une réelle alternative aux solutions acier et béton dites conventionnelles.
Chantiers Chibougamau, acteur majeur de l’industrie québécoise, participe activement à cette évolution en valorisant la principale ressource de la forêt boréale: l’épinette noire.
Grâce à une gestion intégrale de la chaîne de transformation et avec l’appui de sa filiale Nordic Structures, l’entreprise contribue à l’émergence de projets de construction bois de grande hauteur tels que les projets Origine et Arbora.
100 public buildings in local wood, daring the Rural
Françoise Alriq, Fédération Nationale des Communes Forestières, France
Il fallait être audacieux et même innovant pour lancer en 2012, le programme « 100 constructions publiques en bois local ». Pourtant, la Fédération nationale des Communes forestières a dépassé nombre d’a priori, y compris de la filière forêt-bois, pour embarquer les collectivités dans l’aventure et accompagner les projets d’équipements publics. Grâce au réalisme territorial de ses élus, à son réseau d’associations régionales et départementales, le programme s’est déployé jusqu’en 2017. Au départ 3 bâtiments-pilotes, puis des dizaines de projets de collectivités, ont fait émerger des opérations de construction, rénovation ou extension valorisant le bois local.
Contribuer à relancer la filière forêt-bois, redonner de la compétitivité aux entreprises, conforter et même créer de l’emploi, s’engager dans des démarches durables et performantes, être acteurs de la transition énergétique, défendre le bois français pour une valeur ajoutée locale, voilà le pari gagné par les Communes forestières.
Multi-storey Building with engineered wood products. Austrian forerunner experience since the 1990th
Heinz Ferk, Université de Graz, Austria and Bart Ingelaere, CSTC, Belgium
Potential clients are worried about the acoustic performance of apartments in multifamily light weight wooden constructions. Previous experiences in old houses with wooden floors are mainly responsible for this attitude. So new constructions should preferably do even better than traditional heavy weight constructions to counter this attitude. And especially its acoustic performance in the very low frequencies (< 100 Hz) can be worrisome. Some European countries have taken this problem in their requirements. This will shortly be presented The presentation though will focus on the innovative ways of building with lightweight timber frame constructions in Belgium (innovative floors, party walls and façades) with extreme acoustic performances (far better than with heavy constructions). Laboratory results and in situ measurement results will illustrate this. These new technologies are now typically being used in Belgium. The new patented way of building with CLT resulting in no flanking transmission will end this short presentation.
Austria has a forest coverage of more than 46%, which is the third highest forest rate within Europe (Scandinavia 59,8%, Iberian Peninsula 49% ). Nevertheless until 1996 it was not allowed by building regulation to build wood based multistory houses exceeding two stories, although there existed some good historic examples. From that moment on, several factors influenced a political, social and technical development, which led to innovative technical developments and research together with a steady adaption of the building requirements during the following years, which is still going on today.
Laminated timber construction elements, cross laminated timber construction elements met prototype experience with timber frame constructions and new architectural concepts accompanied by a clearly stated political commitment – all these factors made the development of engineered wood based multistory buildings successful in the following years.
As the building requirements also for sound insulation in Austria are high compared to most European countries, besides static, fire and hygrothermal questions especially acoustical challenges had to be met in research and development of the new building constructions.
We succeeded in the development of high performance materials and building constructions for walls, ceilings, etc. together with different systems for reducing the flanking transmission. Already 1996 we used first time load-depended elastic bearings to reduce flanking transmission, “house in house” systems, where continuous slabs were necessary for earthquake resistance design but also module construction concepts.
The talk gives an impression of the “silent timber built” success story, in which Austria took part since the nineties and gives a lookout to international current developments. Much has been achieved, more remains to be done too – the silent timber built story still remains exiting for the future!
Design, materials, products and systems used for wood buildings
Klas Hagberg, WSP, Sweden AB, Sweden and Jean-Luc Kouyoumji, Institut technologique FCBA France
In year 2017 the WWN+ project “Silent Timber Build” is finishing. The project aimed at developing prediction models covering both airborne sound insulation and impact sound insulation for timber structure buildings, using FEM in combination with SEA. The knowledge from the project and the tools developed will facilitate future optimization of timber structure buildings. Additionally, the results provide valuable input to standardized models. The project started by grouping current European timber structures based on their measured acoustical behavior. Hence, the expected sound insulation characteristics in each group can be estimated based on surface mass, and used to compare with modelled results. Subsequently as the model is “verified” it might be refined and the structural assembly is optimized in order to fit to current requirements. Additionally tools are used to design some timber structures presented in the European Database at www.lignum.ch, where a listening tool is integrated, facilitating for users to translate acoustical figures into hearing impression.
Calculation methods for building vibration and acoustic
Delphine Bard, Lund University, Sweden and Catherine Guigou Carter, CSTB, France
La première partie de la présentation concerne la prévision du comportement vibratoire et acoustique des parois en bois ; la seconde se centralise sur la prévision de la performance acoustique du bâtiment.
La prévision du comportement vibro-acoustique des parois en bois est complexe car ces dernières sont composées de multi-cavité, de raidisseurs (montants, solives). De plus, les différents éléments ne sont pas connectés rigidement entre eux. En fonction de la bande de fréquence étudiée, les méthodes de prédiction sont différentes et complémentaires. Cette première partie de la présentation fait le point sur les méthodes actuelles, principalement la méthode des éléments finis et la méthode énergétique SEA. Des exemples de résultats sont montrés.
La nouvelle version des normes européennes EN 12354-1 and -2 (qui deviennent en fait des normes ISO) inclut une méthode de prédiction de la performance acoustique des bâtiments légers en bois. La méthode de prédiction a été discutée et définie globalement dans le cadre de l’action COST FP0702 sous le secrétariat du CSTB et de FCBA. Des données spécifiques caractérisant les jonctions entre parois en bois (isolement vibratoire bidirectionnel normalisé) ont été introduites dans cette nouvelle version. Cette deuxième partie de la présentation fait le point sur cette méthode et les données d’entrées nécessaires.
European Database, acoustic solution examples
Hansueli Schmid, LIGNUM, Switzerland and Nicolas Balanant, Groupe Qualité, France
Linking test results via databases direct to BIM – finally!
Test institutes and engineers generate a large amount of valuable information for construction industry. But how can all this information be applied in practice in a simple and efficient manner?
The concept of www.lignumdata.com is an example of how information on products and components could be digitally provided for broad use. Thanks to the international ifc.-format, the information can be imported directly into every CAD-design program.
With all those information connected to the design, different building models be evaluated, compared and optimized in every aspect which means a whole new planning quality
The construction industry is just at the beginning of the digital transformation – the wood industry is once again part of the “avant garde”!
Easy evaluation methods
Lightweight constructions in wood are complex systems. As there are no national or international standards for such systems, many configurations are possible. Together with the various facade claddings or floor coverings, the number of solutions is infinite. In the French project ACOUBOIS easy evaluation methods and examples which fulfill both, the French regulation and the certification criteria, were produced. A large campaign of in-situ acoustic tests on different wood frame buildings was carried out. The results of this campaign were compared to laboratory tests of walls and floors. As a result, a simple relation has been established, which integrates the implementation and the lateral transmissions of noise.
Enhancing the Knowledge of Vibration and Sound Insulation Performance of Mid- to High-rise Wood Buildings through Field Measurements
Samuel Cuerrier Auclair, FPInnovations, Canada
Globally, the height of wood buildings is constantly rising. Strongly supported by the Canadian government and the industry, several tall wood buildings have been built in Canada since 2010 (6- to 18-storey), with heights varying between 22 to 53 metres.
Vibration and sound insulation performance of mid- to high-rise wood buildings is not a safety issue; rather it affects occupants comfort and proper operation of buildings equipment. It also affects the market acceptance of mid- to high-rise wood buildings. Control of vibration and noise requires design and construction guidelines and solutions which are mainly based on technical knowledge, experience, and database of the building responses to wind excitation, damping ratios and frequencies of the building and building assemblies, and the building sound insulation performance, which have to be determined through in-situ measurements.
To bridge the gap in knowledge, data, and experience of vibration and sound insulation performance of mid- to high-rise wood buildings, FPInnovations has undertaken a comprehensive research program focused on conducting field measurements on such buildings in order to determine the dynamic behaviour of innovative wood-based floors (e.g. natural frequencies and damping ratios). Measurement of the airborne and impact sound insulation performance of some innovative wood floor-ceiling assemblies and of the airborne sound insulation performance of some innovative wood-based walls in these buildings was also performed. Currently, monitoring systems have been installed in two high-rise wood buildings (8-storey and 13-storey) to measure the time history of the building acceleration responses to wind excitation.
Ambient vibration Testing (AVT) was conducted on several tall wood buildings during construction and after completion to measure the building acceleration responses to the ambient excitations. The signals were processed using Operational Modal Analysis (OMA) software to extract frequencies, modal damping ratios, and mode shapes.
Selected floors in each building were tested for their fundamental natural frequencies and 1 kN point load deflection according to ISO standard test method (ISO 2016). The floors tested were bare structure floors without any finish, topping or acoustic membranes.
Selected floor-ceiling and wall assemblies were also evaluated in several buildings to determine their Apparent Sound Transmission Class (ASTC) and Apparent Impact Insulation Class (AIIC) according to ASTM standard methods.
In general, the floors and buildings performed well in terms of their vibration and sound insulation performance. The test data provides useful information to designers. The studies also enhance our knowledge of the vibration performance of tall wood buildings and innovative mass timber floors. It will help expand our database on damping ratios of wood buildings so that design values of wood building damping ratios can be accurately estimated with better confidence.
Workshop Sécurité Incendie
Workshop Sécurité Incendie
Ingénierie de la sécurité incendie
Koji Kagiya, Building Research Institute, Japon
A perspective of R & D on fire safety engineering for timber buildings in Japan will be introduced. Historically, Japan has been suffered from many city fires including earthquake fires due to its traditional wooden construction and densely wooden built-up areas in cities. Hence, by the Japanese building regulation, wooden buildings have been restricted to be built with some requirements for construction depending on their total floor area, number of storeys, areas where they will be built, and so on. Buildings in Japan are classified by the fire safety performance into “Fireproof Buildings”, “Quasi-fireproof Buildings”, “Buildings with Fire-rated Envelope” and others. Fireproof buildings are required to continuously support themselves without corrupting even after fire, while the quasi-fireproof buildings are required to stand only during fire. Therefore they need to stop combustion and charring within the structural members even after the end of fire. It is, therefore, necessary to take measures such as covering with highly fire-resistive materials when using timber for the principal building parts. This is because it assumes earthquake fires where fire service is not expected. So that requirement for the fireproof buildings is harder than the “Fire Resistant Buildings” in most of other countries. On the other hand, innovation on fire safety engineering for timber buildings last few decades make it possible to expand the capability of fire safe use of wood.
Essais de comportement au feu d’une construction massive en bois à deux étages
Bradford K. Douglas, American Wood Council, Etats-Unis
Compartment fire tests have been conducted on a two-story mass timber structure with various combinations of protected and exposed cross-laminated timber (CLT) and glued-laminated timber surfaces. Results from these tests will be used to evaluate building performance, along with occupant and firefighter tenability for egress and suppression efforts, and to provide data necessary to guide further development of relevant code and standard provisions. The following performance parameters were measured during these tests simulating compartment content fires:
1. Performance of the mass timber structure under varying combinations of exposed timber, and passive and active protection
2. Development of smoke and hot gases within the compartment of origin, compartment above the fire compartment, and egress routes, such as the corridor and the stair shaft
3. Temperature rise on various surfaces and material interfaces within wall and floor-ceiling assemblies throughout the structure
4. Radiant heat flux at various points outside the openings of the structure
5. Variation of heat release rate with time
The two-story mass timber structure was constructed as two apartments in a tall wood structure, with each level representing a separate apartment. Each apartment had plan dimensions of approximately 9.1 meters by 9.1 meters, with a ceiling height of 2.7 meters in the bedroom and living room. The kitchen, bathroom, and utility room had dropped ceilings with a height of 2.4 meters. Floor/ceiling assemblies and compartment walls consisted of 5-ply CLT measuring approximately 175 mm thick. CLT walls were continuous from the bottom of the first floor to the top of the second floor, and the CLT floor slab that divided the two levels was supported by protected/concealed ledgers attached to the CLT walls. In addition to bearing on ledgers at the CLT walls, the CLT floor slab was also supported at mid-span by glued-laminated beams and columns. Mass timber elements and ledgers were protected with two layers of 15 mm Type X gypsum wallboard, except for specific testing configurations where impacts of fire exposure on exposed surfaces were evaluated.
For each fire test, the apartment was furnished with typical residential furnishings to achieve an average fuel load density of 550 MJ/m2 throughout. This area-averaged value is based on mean fire load densities plus one standard deviation for the kitchen, bedroom and living room, as determined from a 2011 survey of typical multi-family dwellings in Canada. Identical furnishings and furniture arrangement were used for all tests.
Five fire scenarios were tested. In each test, the fire was started using an ignition package placed next to a wood crib within one of the lower kitchen cabinets. In Test 1, all mass timber surfaces were protected with 15 mm Type X GWB. Test 2 was configured identical to Test 1, except that 30% of the CLT ceilings in the living room and the bedroom were left exposed. Test 3 was identical to Test 1, except that opposing CLT walls, one in the living room and one in the bedroom, were left exposed. In Tests 1, 2 and 3, there was no active fire protection and the fire was allowed to continue without intervention for up to four hours, at which point, the furnishings and contents had been consumed by the fire. For Tests 4 and 5, all mass timber elements were left exposed in the living room and bedroom and the apartment was equipped with an NFPA 13-compliant automatic sprinkler system. In Test 4, the automatic sprinkler system was allowed to activate normally. In Test 5, activation of the sprinkler system was intentionally delayed for 20 minutes to simulate a scenario in which the sprinkler system fails to activate automatically but the system is activated manually by the responding fire service through a direct hook-up to the fire department connection by arriving fire services.
Detailed results for this series of compartment fire tests are being analyzed. A presentation of the results and discussion about the findings will be provided.
Traitement du bois : ignifugation
Arve Valso, Teknos, Norvège
Fire-retardant wood is often classified as fire class B, regardless of whether it is produced according to an impregnation process or by surface treatment. The question is, can all these products be used inside and outside of a building? What are the requirements for documentation for fire retardant wood and is the market aware of these requirements? In Norway, Fire-Retardant wood has been used, both outdoors and indoors for many years. Experience shows that it is important that correct information reaches the end user, both for the purpose of choosing the right product and maintenance.
A lot of research and calculations are done to see if glulam and CLT can meet the fire resistance requirement throughout a total fire. Interesting results show that it is possible to build tall wooden houses in only wood that meet both Fire Resistance and Reaction to Fire claims. Project Mjøstårnet in Norway, which will be 80 meters high, is constructed according to the latest knowledge of how fire safety in wooden high-rise buildings can be designed. Even the cladding will be in wood.
Justification de durée de résistance au feu de 90 et 120 minutes
Christian Dagenais, FPInnovations, Canada
The fire-resistance rating of building components has traditionally been assessed by subjecting a replicate of that component to a standard fire-resistance test, such as CAN/ULC S101 in Canada, ASTM E119 in the United States and ISO 834 in most other countries. Mass timber elements such as solid sawn timbers, glued laminated timber (glulam), structural composite lumber (SCL) and cross-laminated timber (CLT) can provide excellent fire-resistance due to the inherent nature of thick timber members to char slowly and at a predictable rate when exposed to fire. This allows mass timber systems to maintain significant structural resistance for extended durations under fire conditions. The “reduced cross-section method” is the most acknowledged analytical method around the world for evaluating the load-bearing function of mass timber elements exposed to fire (e.g. beams, columns, floor/roof slabs, decking, etc.). A linear charring rate, prescribed in relevant timber design standards, accompanied with a zero strength layer is typically used to calculate the reduced cross-section. Given it’s a mechanics-based method and that a number of tests exceeded 2 hours, there is theoretically no justification for limiting its application to a maximum structural fire-resistance rating (e.g. 2 hours). A large number of test data can be found in the public domain to verify and validate the application of the reduced cross-section method.
Furthermore, some building assemblies may require providing a separating function (insulation and integrity) to provide some level of compartmentation within a building (i.e. fire cells). The separating function of mass timber assemblies is however not as well-documented as their load-bearing function. Special considerations should therefore be given in attempt to ensure these assemblies also fulfill their separating functions, when needed. A number of fire tests on CLT assemblies demonstrated significant separating function, well in excess of 2 hours.
Lastly, connections between structural elements should provide sufficient fire-resistance so that they do not become the critical elements in a structural system. Currently, the Eurocode 5: Part 1-2 limits the design procedure for timber connections to 60 minutes when exposed to a standard fire. One can presume that any metallic fasteners located within the residual cross-section would not be severely impacted from thermo-mechanical degradation and would thus still fulfill its load-bearing function. However, very little test data for fire duration exceeding 1 hour can be found in the public domain. There is a need to rationalize the fire-resistance design of connections for tall wood building, which would most likely require 90 and 120 min fire-resistance.
This presentation will provide background information relating to the calculation of the load-bearing and separating functions of mass timber elements. It will also provide recommendations related to connections as well as information from recent research activities and test data conducted in support to tall wood buildings.
Propagation feu façade
Stéphane Hameury,CSTB, France
High-rise wooden buildings are gaining interest worldwide as a response to global climate changes. Traditional architecture and traditional ways of building are indeed irreversibly going to shift towards the development of green buildings targeting low environmental burden and low energy consumptions. This in turn will tremendously increase the demand for bio-based materials, as it is already the case for wooden products. This paradigm shift will undoubtedly create modifications in the response of buildings against fire occurrence, growth and spread and the recent fire event at the Grenfell Tower in London provides daily proof that we need to improve our fire safety strategies in regards to the increase amount of combustible materials present in our buildings that we are going to face in the near future.
As previously explained, fire safety of facades is an issue and the international scientific community recognized the need for further research. Consequently, the CSTB decided to launch, together with RISE in Sweden, the first international seminar addressing the fire safety of facades in 2013. In the meantime, the CSTB has led during the last five years a national research project under a grant agreement with the wood industry to provide the wood construction community with adapted design of wooden facades to mitigate the risk of fire spread, especially when addressing high-rise buildings. Intermediate and large scale fire tests of wooden facades with different cladding materials, surface treatments, fire barriers, insulating materials and structures were performed.
During the workshop, the talk of Stéphane Hameury will share the knowledge acquired through the research results and will present the guidelines based on the research work which have been recently endorsed by the French public authorities in February 2017.
Propagation feu façade Bâtiments multiétages bois en zone sismique
Ario Ceccotti, Université de Venise, Italie
Cross-laminated timber (a-k-a CLT or X-Lam) panels coupled with mechanical connections and fasteners are the basic elements for making residential multi-storey buildings capable to survive severe earthquakes saving lives with almost no-damage or very little one.
The Author presents in a simple way how this kind of buildings can be designed properly up to seven storeys, controlling strength, stiffness, dissipation of energy and accelerations at floors.
Design assumptions are confronted and validated by test data from a series of original dynamic tests on a real scale 7 floor CLT building – 100 square meters per floor, 250 tons total weight – on a 6 DOF shaking table.
Original movies of the tests will complement the presentation.
Workshop Risques sismiques
Workshop Risques sismiques
Analyse et conception sismique des systèmes constructifs
Massimo Fragiacomo, Université de l’Aquila, Italie
Despite the extensive use of mass timber structural systems in Europe and oversees, there are just few provisions for seismic design in current design codes. A revision of the Section 8 – Timber Structures of the Eurocode 8 – Design for seismic action is currently under way, with special emphasis on providing Capacity base design rules, behaviour factors, and overstrength factors for different timber structural systems. The presentation will provide the basics of seismic design of timber buildings, with special attention to mass structural systems. The dissipative mechanisms will be identified, based on the results of full-scale shaking table and component tests recently carried out. Proposals for the behaviour factor will also be made, together with capacity based design principles at the building and connection level. Values of the ovestrength factors derived from experimental tests recently carried out will be given, along with a design proposal for the dissipative connections.
Défis pour la conception d’immeubles grande hauteur bois en zone sismique
Andy Buchanan, Université de Christchurch, Nouvelle-Zélande
This paper describes major challenges in the lateral load design of tall timber buildings. “Tall” means 10 storeys or more, although many of the challenges also apply to timber buildings over 4 or 6 storeys tall, becoming more severe as the buildings get taller.
Structural design starts with the selection of structural form and structural materials, the major objective being to control lateral displacements under wind and earthquake loading. Lateral displacements are much easier to control with structural walls rather than with moment frames.
The design challenges include all the structural engineering difficulties of wind and earthquake design, including displacement control, capacity design, ductility, damping, design of diaphragms, and allowance for higher mode effects. The Pres-Lam building system which uses post-tensioned timber frames and walls is described briefly, showing the major advantages, especially for buildings with highly loaded structural walls.
While solutions to all these challenges do exist, they can often be difficult to find or implement. Top quality advice and engineering judgement is always required.Proposed 15-storey CH2 building,Ottawa, Canada.
Immeubles grande hauteur : l’expérience canadienne
Marjan Popovski, FPInnovations, Canada
The Framework Project is a 12-story, 135ft (41m) tall mixed use building to be constructed essentially entirely out of mass timber, including both the gravity and lateral force-resisting systems, in a region of high seismicity in the United States (Portland, Oregon). Utilizing performance-based seismic design and nonlinear response history analysis, the structure’s rocking/re-centering cross laminated timber (CLT) walls were designed for enhanced seismic objectives: stringent criteria on deformation-controlled elements, replacement of energy dissipaters, limitations on residual drift, and a project-specific testing program.
The momentum behind construction of mass timber buildings provides an opportunity to promote low-damage design. Extending rocking mass timber walls to taller buildings is feasible; however, it requires an additional level of thoughtful design, explicit analysis and testing, and careful detailing.
Exigences sismiques et état actuel de la construction moyenne hauteur en bois au Japon
Takahiro Tsuchimoto, Building Research Institute, Japon
The Act for Wood Use Promotion in Public Buildings was established at 2010 in Japan. The large scale and mid-rise timber construction is considered as a choice to promote wood utilization. Because Japan is one of the highest seismic area, the seismic requirements for buildings are severe. The seismic requirement provided by the Building Standard Law (BSL) is that the building have to prevent to deform beyond the damage limit under the rarely occurred strong earthquake and to collapse under the extremely rarely occurred strong earthquake. So, the mid- or high-rise timber construction cannot be built in Japan with the similar design and specification to in European and North American countries. The research and development project for standardization of CLT panel construction has completed last year. Our institute, BRI started the R & D project for mid- and high-rise timber construction. The procedure to standardize the CLT, the outline of the started project and the recent case studies of mid-rise timber construction in Japan will be presented.