A Canadian research network to increase the use of wood in multi storey buildings (NEWBuildS)

Transcription

1 A Canadian research network to increase the use of wood in multi storey buildings (NEWBuildS) Prof. Y. H. Chui Scientific Director University of New Brunswick Dec 9 th,

2 Forest Sector R&D Initiative 2008 Federal budget allocated funding ($35 m) to NSERC to support research with the purpose of transforming the forest industry Forest Sector R&D Initiative Four NSERC research networks established by FPInnovations: Value Chain Optimization Innovative Green Fibre Products Biomaterials and Chemicals Innovative Wood Products and Building Systems (NEWBuildS)

3 Goal of NEWBuildS Network on Engineered Wood based Building Systems ($1.06m/yr over 5 years) To increase the use of wood based products in multi storey and nonresidential buildings through: provision of design and analysis tools; removal of building code barriers; and provision of innovative building solutions

4 Wood was used in multi storey buildings Modern building codes restrict use of wood in multi- storey buildings ---- Network is to revive interest in using wood in multi-storey 67.1m Sakyamuni Pagoda in buildings Yingxian, China (built in 1056) - Tallest wood building in the world 30m Commercial building, Vancouver (built in 1905) - Tallest wood building in Canada

5 Increased interest world wide in specifying wood Carbon neutral, renewable (green) Reduced construction time ease of prefabrication Lower mass cheaper foundation, lower seismic force & addition of storeys

6 Multi storey buildings modern construction 8-storey cross laminated timber structure atop 1-storey concrete frame, London, UK (2008) - Tallest wood residential building in the world 6-storey laminated timber building with concrete shear walls, Quebec City (2009) - Tallest wood building in Canada in recent times

7 High rise wood building 1 (planning) 20 storey cultural centre building in Kirkenes, Norway Columns and beams are glulam Cross laminated timber floor panels (Source : Reiulf Ramstad Architects)

8 High rise wood building 2 (planning) LifeCycle Tower, Austria The 20 storey structure is 70m high, 43m long and 27m wide These multi-storey wood buildings are the exceptions....research Core walls, floor beams and is required to make wood one of the outside columns are glulam norms allowed by building codes Concrete floor slab (Source : eklynewsletter

9 What is required to prove that wood is a viable material for multi storey and non residential buildings?

10 Outcome of NEWBuildS Network Output A series of technical tools System Models Fire Application Structural Serviceability Building envelope Impact Design Process Building Codes Design Standards Product Evaluation Techniques CLT Product Standard

11 NEWBuildS themes T1. Cross laminated timber (CLT) material characterization and structural performance T2. Hybrid building systems structural performance T3. Building systems fire, acoustic and vibration serviceability T4. Building systems durability, sustainability and enhanced products

12 Theme I: Cross laminated timber (CLT) Material characterization and structural performance Theme leader: Frank Lam University of British Columbia Co leader: Mohammad Mohammad FPInnovations

13 CLT Panels Timber planks stacked crosswise in layers (glued or nailed), mm thick Light weight alternative to concrete slab and concrete tilt-up walls An accepted product in Europe (>9 manufacturers)

14 Advantages of CLT Panels 9-storey CLT apartment building in London completed in 27 days with a crew of 4 Factory produced with high precision CNC machines Fast on-site erection leads to reduced construction cost

15 Strong interest in North America Two CLT production facilities are at a planning stage in Canada alone First CLT building rerected in North Carolina, USA in November 2010 Joint USA-Canada Committee to develop standardization information manufacturing and design information

16 Challenges in introducing CLT Current products - 1-d member + thin panels New test material property evaluation methods CLT - thick plate Source : EMPA Source : CWC Different design tools and construction method

17 Other challenges structural Low rolling shear strength Connection design Seismic performance shaketable test in Japan

18 Other challenges nonstructural Fire resistance Hygro-thermal performance

19 Expected outcome Development of product evaluation procedures Network projects: Test method for measuring rolling shear strength (Gong, UNB) Test method of measuring two way bending properties using vibration technique (Chui and Gong, UNB)

20 Expected outcome Product performance and improvement Network projects: Optimum CLT product design using Canadian species (Lam, UBC) Improved rolling shear resistance using mechanical fasteners (Lam, UBC)

21 Expected outcome Understanding structural performance of CLT construction Network projects: CLT connections (Smith, UNB) Lateral resistance of CLT wall (Haukaas, UBC) Behaviour of horizontal CLT system under outof plane bending (floor) and in plane (diaphragm) (Chui, UNB & Lam, UBC) Long term performance of CLT under sustained load (Lam, UBC) Behaviour of CLT buildings under seismic load (Lam, UBC)

22 Link to other themes System analysis models Theme 2 Hybrid construction Theme 1 -CLT Fire performance and floor vibration Theme 3 Fire, vibration & acoustics Hygrothermal performance of CLT panels Theme 4 Durability and sustainability

23 Theme 2 Hybrid building systems Structural performance Theme leader: Ian Smith University of New Brunswick Co leader: Conroy Lum FPInnovations

24 Projects Basket 1 Basket 2 Light mid-rise light wood frame buildings Outside-the-box Innovations

25 Mid rise light wood frame buildings Storey limit was raised from 4 to 6 in 2009 in British Columbia other provinces as well as national building code may follow

26 Mid rise light wood frame buildings Design guidelines are needed Shrinkage deformation Lateral displacement Δ6' Four storey wood frame Δ6 Δ5 Six storey wood frame Six storey wood frame Δ4' Δ4 Δ4 Δ3 Δ2 Δ3 Δ2 Four storey wood frame Δ1 Δ1 Foundation Shrinkage related deformation Foundation Deflection and natural period

27 Mid rise light wood frame buildings Design guidelines are needed for mixed construction: Wood + concrete core Light wood frame structure Masonry or concrete core as stairwell and elevator shaft

28 Innovations Combining wood with other materials (Hybrid) Steel Glulam Concrete New gymnasium at University of New Brunswick Timber + Steel + Concrete

29 Innovations Multi storey buildings with concrete/steel + wood in fill Reinforced concrete frame with wood in-fill panels Source: European Wood China

30 Innovative concept Multifunctional compartmentalization Roof Thermal jacket Cladding Subspace: single occupancy isolated from neigbours internal isolations possible modular prefab timber internally subdivided RC core Isolated timber compartments RC concrete core containing service shafts ISOLATED COMPARTMENTS (e.g. fire, vibration, sound, structural) Foundation (Source: Smith and Frangi 2008)

31 Expected outcome Understanding structural response of mid rise, light wood frame buildings (1) Network projects: Integration of alternative bracing elements built with gypsum wall board and portal frame (Chui, UNB) Diaphragm action in light wood frame platform construction (Lam, UBC)

32 Expected outcome Understanding structural response of mid rise, light wood frame buildings (2) Network projects: Predicting lateral drift and natural period of mid rise wood and hybrid buildings (McClure, McGill U. & Chui, UNB) Interaction of light wood frame with stiff core under seismic load (Chui, UNB)

33 Expected outcome Construction technologies for combining wood with other materials (1) Network projects: Techniques for forming multi functional construction interfaces in hybrid buildings (Smith, UNB) Wood concrete hybrid buildings (Bartlett & Hong, U. Western Ontario) Wood steel hybrid buildings (Stiemer & Tesfamariam, UBC)

34 Expected outcome Construction technologies for combining wood with other materials (2) Network projects: Hybrid floor with post tension timber beam and concrete slab (Gauvreau & Cooper, U. Toronto) Movements and deformation incompatibilities of materials in heavy frame timber buildings (Smith, UNB)

35 Theme 3 Building Systems Fire Performance, Acoustic and Vibration Theme Leader: George Hadjisophocleous Carleton University & Co Leader: Steve Craft FPInnovations

36 Construction details impact on fire, vibration and acoustics Vibration Fire Direct Transmission Acoustic Flanking Transmission Flanking Transmission

37 Challenges Concern about fire performance of wood buildings is one of the major reasons for limiting the storey height of wood buildings Examples of building code barrier Ex 1 Non-residential buildings Non combustible Combustible Fire separations No fire resistance requirement Supporting walls: no rating Fire separations 45 min fire resistance Supporting walls: rating of 45 min Ex 2 - Walls of high-rise building must be noncombustible

38 Challenges Potential issues about acoustics and vibration transmission from one unit to another in a multi storey buildings are unknown Direct Transmission Flanking Transmission Flanking Transmission

39 Expected outcome Tools for predicting fire and smoke spread in buildings, and the possible loss of structural capacity Network projects: Fire risk analysis (Hadjisophocleous, Carleton U.) Rationalization of building code fire safety requirements for mid rise buildings (Zalok & Hadjisophocleous, Carleton U.) Fire behaviour of CLT panels (Hadjisophocleous, Carleton U.) Fire performance of timber connections (Hadjisophocleous, Carleton U.)

40 Expected outcome Design details to avoid annoying acoustic and vibration in CLT and mid rise buildings without compromising fire safety Network projects: Vibrational performance of CLT floors (Chui, UNB) Sound insulation of innovative wood building systems (Nightingale, Carleton U./NRC & Hodgson, UBC)

41 Theme 4 Building systems Sustainability, durability and enhanced products Theme Leader: Paul Cooper University of Toronto & Co Leader: Bob Knudson FPInnovations

42 Challenges Environmental performance is critical for acceptance by rchitects and engineers (e.g. LEED, Green Globes) Other major technical concern in wood multi storey buildings is relate to: Biological deterioration associated with water ingress

43 Expected outcome Environmental impact of using wood products in mid rise construction Network projects: Environmental performance of innovative wood building systems using life cycle assessment (Beauregard, Laval U.)

44 Expected outcome Design to prevent moisture related building envelope problems Network projects: Developing durable building envelope assemblies for CLT (Ge, Ryerson U. & Straube, Waterloo U.) Effectiveness of overhang on reducing wind driven rain wetting for mid rise buildings (Ge, Ryerson U.)

45 Expected outcome Treatments that enhance fire and durability performance of woodproducts second line of defense Network projects: Intumescent coatings to protect engineered wood products (Koubaa, U. Quebec) Borate pretreatments to protect building envelope components from decay (Cooper, U. Toronto)

46 Profile of NEWBuildS

47 University research partners (11) (23 researchers) Université du Québec en Abitibi-Témiscamingue

48 Industry and government research partners (15) (2) Institute for Research in Construction (1)

49 Non technical outcome To strengthen the national research capacity in support of the wood industry: multi disciplinary team of 38 researchers 9 new researchers (acoustics, building envelope, fire, architecture, steel, concrete training opportunities for about 60 graduate students and PDF conducting 36 research projects To revive interest in timber structure design curriculum in Canadian universities at u/g and graduate level

50 Thank You & Questions?