Fire%Safety%of%Timber%Buildings:% A%Research%Review% David&Barber& Arup,&Washington&DC& 24=26&September&2014&

Transcription

1 Fire%Safety%of%Timber%Buildings:% A%Research%Review% David&Barber& Arup,&Washington&DC& 24=26&September&2014&

2 Recent&architectural&trends&in&sustainable&urban& densificaeon&have&spurred&a&movement&toward& increasingly&larger&buildings&made&from&ember&products&or& a&combinaeon&of&wood&and&other&materials.&many&ember& building&concepts&are&moevated&by&their&suggested& advantages&in&sustainability&resuleng&from&the&use&of&wood& as&a&renewable&and&low=carbon&construceon&material.&in& furthering&wood's&evolueon&as&a&structural&material&in& urban&selngs,&designers&are&interested&to&bemer& understand&the&implicaeons&of&ember&use&with&regard&to& fire&and&life&safety.&&ensuring&&occupant&safety&and&the& proteceon&of&property&requires&assessing&the&fire& performance&of&structural&systems&and&design&applicaeons.& This&presentaEon&will&include&the&findings&of&a&study& performed&in&coordinaeon&with&the&fire&proteceon& Research&FoundaEon.& && Disclaimer: This presentation was developed by a third party and is not funded by WoodWorks or the Softwood Lumber Board.

3 1. & Explain&the&current&state&of&fire&and&life&safety&codes&and&standards&as&they&relate&to& allowing&ember&as&a&structural&material.& 2.&Describe&the&current&understanding&of&fire&performance&of&tall&Ember&buildings,& including&results&of&fire&teseng&and&examples&of&high=rise&ember&buildings.& 3.&IdenEfy&areas&for&future&tesEng&and&research&needed&to&demonstrate&safety&in&tall& Ember&buildings.& 4.&Understand&the&importance&of&effecEve&risk&communicaEon&with&Ember&building& stakeholders.& &

4 The&Wood&Products&Council &is& a&registered&provider&with&the& American&InsEtute&of&Architects& ConEnuing&EducaEon&Systems& (AIA/CES),&Provider&#G516.& &! Credit(s)&earned&on&compleEon& of&this&course&will&be&reported&to& AIA&CES&for&AIA&members.& CerEficates&of&CompleEon&for& both&aia&members&and&non=aia& members&are&available&upon& request.& & & This&course&is&registered&with& AIA&CES&for&conEnuing& professional&educaeon.&as& such,&it&does&not&include& content&that&may&be&deemed& or&construed&to&be&an& approval&or&endorsement&by& the&aia&of&any&material&of& construceon&or&any&method&or& manner&of& handling,&using,&distribueng,& or&dealing&in&any&material&or& product.& QuesEons&related&to&specific&materials,& methods,&and&services&will&be&addressed& at&the&conclusion&of&this&presentaeon.& & &

5 Introduction Buildings have to be safe during building use Fire safety includes: - Safety from fire - Occupant evacuation - Emergency operations - Safety from structural failure - Structural stability 6

6 Introduction Everyone is aware that wood burns 7

7 Timber Fire Performance Fire performance - Light timber vs. heavy timber 8

8 Timber Fire Performance Light timber framing - 2x studs and joists - I-joists, trusses Stick frame construction 9

9 Timber Fire Performance Fire protection - Light timber 10

10 Timber Fire Performance Heavy timber frame products meeting prescriptive min. sizes - Solid sawn - Engineered wood products Glue laminated wood (Glulam) Laminated Veneer Lumber (LVL) 11

11 Timber Fire Performance Heavy timber frame products - Engineered wood products Cross Laminated Timber (CLT) 12

12 Timber Fire Performance Fire protection - Heavy timber Sacrificial char layer Solid cold timber 13

13 Timber Fire Performance Fire performance - Light timber vs. heavy timber 14

14 Timber Fire Performance Charring - Well-understood - Predictable - ~0.025 in/min [0.7mm/min] 15

15 Timber Fire Performance Timber Frame Cardington, UK - Fire resistance of a mid-rise timber building 16

16 Timber Fire Performance Natural fire testing: - Light timber framing - Combustible lining vs. gypsum lining - Sprinklered vs. non-sprinklered Combustible lining Gypsum board lining Sprinkler protection 17

17 Timber Fire Performance CLT assemblies - Charring rate consistent with wood (~0.025 in/min [0.7mm/ min]) - Predictable behavior - Improved performance with gypsum board protection 18

18 Timber Fire Performance Fire protection for connections 19

19 Timber Fire Performance Timber composite assemblies - CLT box beams - Fire performance based on testing - Over 2-hour ratings for assemblies 20

20 Timber Fire Performance Fire performance - Composite members - Timber concrete floors 21

21 Further Research Penetrations - Fire-stopping 22

22 Further Research Contribution of timber to room fires - Delamination - Self-extinguishment 23

23 Further Research Perception of risk - Improved understanding of fire performance of timber needed across the industry 24

24 Building Regulations in Timber International regulations 25

25 Building Regulations in Timber International regulations Country Applicable Building Code Maximum # of Stories Sprinklered Unsprinklered Australia 2013 Building Code of Australia (BCA) 3 3 Austria Austrian Building Codes 8 (*72 feet) 3 Canada 2010 National Building Code of Canada (NBCC) 4 3 Germany 2012 Federal Building Code 8 (*59 feet) 3 Sweden 2013 Planning and Building Act 8 2 United Kingdom 2010 Building Regulations 5** 4** United States 2012 International Building Code (IBC) 5 4 * Indicates a height limit in addition to a maximum story limit 26

26 Building Regulations in Timber Prescriptive Design - Code changes Performance based design - Alternative solution to prescriptive codes 27

27 Gaining Approval Option 1 Prescriptive route - TF 2000, UK - FPInnovations, North America Long term solution - Requires significant justification - Testing, understanding, discussion, agreement - Takes a significant amount of time - 3-year code cycles (USA) 28 Fire Safety

28 Gaining Approval Option 2 Performance route - All tall timber structures to date - UK, Australia, Europe, Canada - Up to the discretion of the approval authority - Technical justification for safety - No different to any other innovative building solution 29 Fire Safety

29 Gaining Approval Fire protection strategies - Passive - Encapsulation - Compartmentation - Egress - Active - Sprinklers - Detection and alarm 30

30 Gaining Approval Improved understanding of fire risks - Penetrations - Connections - Contribution exposed timber to room fires - Potential for self-extinguishment 31 Fire Safety

31 Gaining Approval Address Perception of risk - Improved understanding - Technical justification - Risk communication 32

32 Risk Communication We cling to the myth that timber construction presents risks, while concrete and steel do not. Nonsense. Every material presents risks, but we manage them in different ways - Russell Fortmeyer, Arup 33

33 Timber Buildings Heavy timber frame construction - Post and beam construction 34

34 Timber Buildings Heavy timber frame construction - CLT Panelized construction 35

35 Timber Buildings Heavy timber frame products - Composite wood products Post-tensioned timber 36

36 Timber Buildings Heavy timber frame products - Composite wood products Timber-concrete composite floors 37

37 Contemporary Examples Panelized construction - Stadhaus, London, UK,

38 Contemporary Examples Panelized construction - Stadhaus, London, UK,

39 Contemporary Examples Panelized construction - Forte Building, Melbourne, Australia,

40 Contemporary Examples Panelized construction - Forte Building, Melbourne, Australia,

41 Contemporary Examples Post and beam construction - Life Cycle Tower One, Austria,

42 Contemporary Examples Post and beam construction - Wood Innovation Design Centre, Prince George, Canada,

43 Timber Buildings Global precedent 44

44 Future Timber Buildings Feasibility studies Office Building of the Future, CEI Architecture, 2013 Timber Tower, SOM,

45 Future Timber Buildings Feasibility examples - Case for Tall Wood 30-story high-rise, Michael Green Architecture,

46 Next Steps USDA Grant story timber building - $2mil for design development - Full design team Holistic Timber Design - Acoustics - Facades - Structural - Seismic, vibrations, stability - Sustainability - Fire / Life Safety 47

47 Acknowledgements Fire Protection Research Association National Fire Protection Association WoodWorks American Wood Council 48

48 This&concludes&The&American& InsEtute&of&Architects&ConEnuing& EducaEon&Systems&Course& David%Barber% Arup,%Washington%DC%