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

Prof. Y. H. ChuiScientific Director

University of New Brunswick

Dec 9th, 2010

www.NEWBuildSCanada.ca

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)

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 non‐

residential buildings through:– provision of design and analysis tools;– removal of building code barriers; and– provision of innovative building solutions

Wood was used in multi‐storey  buildings

30m Commercial building, Vancouver (built in 1905)- Tallest wood building in Canada

67.1m Sakyamuni Pagoda in Yingxian, China (built in 1056)- Tallest wood building in the world

Modern building codes restrict use of wood in multi- storey buildings ---- Network is to revive interest in using wood in multi-storey buildings

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

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

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)

High‐rise wood building – 2 (planning)

(Source : http://www.building.co.uk/story.asp?storycode=3162205&origin=bldgwe eklynewsletter

• LifeCycle

Tower, Austria

• The 20‐storey structure is  70m high, 43m long and 

27m wide

• Core walls, floor beams and  outside columns are glulam

• Concrete floor slab

These multi-storey wood buildings are the ‘exceptions’…..…..research is required to make wood one of the ‘norms’ allowed by building codes

What is required to prove that wood  is a viable material for multi‐storey 

and non‐residential buildings?

Outcome of NEWBuildS

A series of technical

tools

Structural

Fire

Serviceability

Building envelope

Application

Design Process

Building Codes

Design Standards

Impact

System Models

Network Output

Product Evaluation Techniques

CLT Product Standard

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

Theme I: Cross laminated  timber (CLT) –

Material 

characterization and structural  performance

Theme leader:  Frank Lam

University of British Columbia

Co‐leader: Mohammad Mohammad

FPInnovations

Timber planks stacked crosswise in layers (glued or nailed), 50 - 600 mm thick Light weight alternative to concrete slab and concrete tilt-up walls

CLT PanelsCLT Panels

An accepted product in Europe (>9 manufacturers)

Factory produced with high precision CNC machinesFast on-site erection leads to reduced construction cost

Advantages of CLT PanelsAdvantages of CLT Panels

9-storey CLT apartment building in London – completed in 27 days with a crew of 4

Strong interest in North America Strong interest in North America 

Two CLT production facilities are at a planning stage in Canada aloneFirst CLT building rerected in North Carolina, USA in November 2010Joint USA-Canada Committee to develop standardization information –manufacturing and design information

Challenges in introducing CLT

CLT

- thick plate

Current products

- 1-d member + thin panels

Source : EMPA

New test material property evaluation methods

Source : CWC

Different design tools and construction method

Other challenges ‐

structural

Low rolling shear strength

Connection design

Seismic performance – shaketable test in Japan

Other challenges – non‐ structural

Fire resistance Hygro-thermal performance

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) 

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)

Expected outcomeUnderstanding structural 

performance of CLT construction• Network projects: 

– CLT connections (Smith, UNB)

– Lateral resistance of CLT wall (Haukaas, UBC)– Behaviour

of horizontal CLT system under out‐

of‐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)

Link to other themesLink to other themes

Theme 1 - CLT

Theme 2 – Hybrid

construction

Theme 3 – Fire, vibration & acoustics

Theme 4 – Durability and sustainability

System analysis models

Fire performance and floor vibration

Hygrothermal performance of CLT panels

Theme 2 – Hybrid building systems –

Structural performance

Theme leader:  Ian Smith

University of New Brunswick

Co‐leader:Conroy LumFPInnovations

Basket 2

Outside-the-box Innovations

Light mid-rise light wood frame buildings

Basket 1

Projects

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

Mid‐rise light wood frame  buildings

• Design guidelines are needed

Δ4

Foundation

Δ3

Δ2

Δ1

Δ6

Δ5

Δ4

Δ3

Δ2

Δ1

Shrinkage deformation

Four storeywood frame Six storey

wood frameΔ4'

Foundation

Δ6'

Lateral displacement

Four storeywood frame

Six storeywood frame

Shrinkage related deformation Deflection and natural period

Mid‐rise light wood frame  buildings

• Design guidelines are needed for  mixed construction:

‐

Wood + concrete core

Masonry or concrete coreas stairwell and elevator shaft

Light wood frame structure

Innovations – Combining wood  with other materials (Hybrid)

New gymnasium at University of New Brunswick – Timber + Steel + Concrete

Steel

Glulam

Concrete

Innovations ‐

Multi‐storey buildings  with concrete/steel + wood in‐fill

Source: European Wood China

Reinforced concrete frame with wood in-fill panels

ISOLATED COMPARTMENTS (e.g. fire, vibration, sound, structural)

Innovative concept ‐

Multi‐ functional compartmentalization

Roof

Isolatedtimbercompartments

Foundation

RC

con

cret

e co

re c

onta

inin

g se

rvic

e sh

afts

CladdingSubspace:• single occupancy

• isolated from neigbours• internal isolations possible

• modular prefab timber• internally subdivided

Thermal jacket

RC

cor

e

Roof

Isolatedtimbercompartments

Foundation

RC

con

cret

e co

re c

onta

inin

g se

rvic

e sh

afts

CladdingSubspace:• single occupancy

• modular prefab timber• internally subdivided

Thermal jacket

RC

cor

e

(Source: Smith and Frangi 2008)

Expected outcomeUnderstanding 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)

Expected outcomeUnderstanding 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) 

Expected outcomeConstruction 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)

Expected outcomeConstruction 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)

Theme 3 Building Systems ‐

Fire Performance, Acoustic and  Vibration

Theme Leader:

George Hadjisophocleous

Carleton University

&

Co‐Leader:

Steve Craft

FPInnovations

Construction details impact on  fire, vibration and acoustics

Direct Transmission

Flanking Transmission

Flanking Transmission

Direct Transmission

Flanking Transmission

Flanking Transmission

Vibration

Fire

Acoustic

Challenges

Non‐combustible Combustible

Fire separations Fire separations

No fire resistance requirement 45‐min fire resistance

Supporting walls: no rating Supporting walls: rating of 45‐min 

• 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 barrierEx 1 – Non-residential buildings

Ex 2 - Walls of high-rise building must be non- combustible

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

Direct Transmission

Flanking Transmission

Flanking Transmission

Expected outcomeTools 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.)

Expected outcomeDesign 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)

Theme 4  Building systems –

Sustainability, durability and  enhanced products

Theme Leader:

Paul Cooper

University of Toronto

&

Co‐Leader:

Bob Knudson

FPInnovations

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

Expected outcomeEnvironmental 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.)

Expected outcomeDesign 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.)

Expected outcomeTreatments that enhance fire and 

durability performance of wood‐ products –

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)

Profile of NEWBuildS

University research partners (11)  (23 researchers)

Université du Québec en Abitibi-Témiscamingue

Industry and government  research partners

Institute for Research in

Construction

(15)

(2)

(1)

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 

Thank You &

Questions?

www.NEWBuildSCanada.ca