Canadian Wood Council G063

Transcription

1 Canadian Wood Council G063 Full-Scale Fire Demonstration of a Mass Timber Shaft for use in Tall Buildings L. Ranger (Osborne), M.A.Sc, Scientist, FPInnovations, Serviceability & Fire, Advanced Building Systems November 24, 2015

2 Credit(s) earned on completion of this course will be reported to AIA CES for AIA members. Certificates of Completion for both AIA members and non-aia members are available upon request. This course is registered with AIA CES for continuing professional education. 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 construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

3 Course Description There are current efforts in Canada and the United States to build taller wood buildings in North America. Because these types of buildings are not currently permitted by the prescriptive provisions in the National Building Code of Canada, Alternative Solutions have to be followed to demonstrate that the design provides equivalent or better levels of safety than what is currently required by the code. To support the construction of a tall wood building in Quebec, FPInnovations, through funding from the Ministère des Forêts, de la Faune et des Parcs of Québec, conducted a full-scale demonstration of a severe fire in an apartment unit adjacent to an exit stair shaft. The 3-storey structure was constructed and evaluated at National Research Council Canada. The intent was to show that a building using mass timber construction, including in the stair shaft, can easily resist fire for 2 hours; currently required to be of noncombustible construction. This presentation will discuss current building regulations related to tall wood buildings and give a detailed account of the demonstration fire that was performed. As an outcome of this demonstration and other research efforts, Québec is now the first Canadian province to allow buildings up to 12-storeys to be built of mass timber construction.

4 Learning Objectives At the end of the this course, participants will be able to: Key learning points: Participants will review some of the limits of the prescriptive provisions in the National Building Code of Canada as they relate to tall wood buildings. Participants will understand how an Alternative Solutions path can be followed to demonstrate that a design provides equivalent or better levels of safety than what is currently required by the code. This presentation will discuss current building regulations related to tall wood buildings and give a detailed account of the demonstration fire that was performed. The intent was to show that a building using mass timber construction, including in the stair shaft, can easily resist fire for 2 hours; currently required to be of noncombustible construction. Participants will learn that the outcome of this demonstration and other research efforts, is that Québec is now the first Canadian province to allow buildings up to 12-storeys to be built of mass timber construction.

5 Full-Scale Fire Demonstration of a Mass Timber Shaft for use in Tall Buildings Lindsay Ranger (Osborne), M.A.Sc Wood Solutions Fair Metro Toronto Convention Centre November 24 th, 2015

6 Outline FPInnovations 2015 NBCC Mid-Rise Provisions Resources & Guides Tall Building Code Requirements Demonstration projects Research to Support TWB Construction Fire Resistance Tests Full-Scale Mass Timber Shaft Fire Demonstration 6

7 FPInnovations Private not-for-profit research center Specialized in creation of scientific solutions in support of: Forest operations, Wood Products Manufacturing, Advanced Building Systems, Pulp & Paper, etc. Across Canada 7

8 2015 NBCC Mid-Rise Provisions Increased height Increased max. building areas Exit stair shafts can be of combustible construction, except ON and QC MH 2015 Reference Guide 8

9 Resources and Guides Handbooks provide information for wood-frame and CLT design Test data used to: Validate/refine calculation methods from CLT Handbooks Facilitated Code implementation in North America - CLT already implemented in 2015 NDS, and soon in CSA O86 - CLT recognized in 2015 IBC as Type IV construction 9

10 RBQ Guide for 12 Storey Mass Timber Essentially a provincially approved alternative solution Requested by gov. Based on significant mass timber research Fire performance Mass timber exit shafts 10

11 RBQ Guide for 12 Storey Mass Timber Full 12 storey mass timber or hybrid, or 12 storey timber over 1 storey concrete Mass timber or hybrid construction (12 storeys) C,D Area: 1500 m 2 A2, E Area: 1500 m 2 Podium: Noncombustible construction - concrete C,D: Mass timber or hybrid construction Area: 1500 m 2 A2, E, parking garage: -noncombustible -unlimited area Batiments de construction massive en bois d au plus 12 etages 11

12 Tall Building Code Requirements Exit stairs in buildings greater than 6 storeys Non-combustible construction 2 h FRR - Mass timber can easily achieve FRR Installation of automatic sprinklers (NFPA 13) 12

13 Tall Building Code Requirements Exit stairs need to maintain their structural integrity and tenable conditions Smoke and temperature Evacuation Use by fire services Tall wood buildings can achieve same level of safety as buildings of NC construction 13

14 Demonstration Projects NRCan/CWC TWB demonstration projects Vancouver, BC 18 storeys, residential Québec City, QC 13 storeys (12+1) residential U.S. Tall Wood Building Prize Competition New York City, NY 10 storeys commercial, residential Portland, OR 12 storeys retail, office, residential 14

15 Acton Ostry Architects Nordic Structures SHoP Architects 15

16 Demonstration Project - Origine Nordic Wood Structures, EBC, Yvan Blouin Architect, GHL Consultants Québec City Glulam and CLT 13 storey (12+1), Group C Challenges Code compliance Combustibility sentiment CLT vertical shafts Nordic Structures 16

17 Full-scale Demonstration Fire testing requested by: Association des chefs en sécurité incendie du Québec (ACSIQ) Régie du bâtiment du Quebec (RBQ) Demonstrate actual fire performance of fullscale structure Facilitate adoption of exit shafts using mass timber construction 17

18 Full-scale Demonstration Support approval and construction of Alternative Solution Fire severity, spread of smoke, building integrity Designed to challenge wall between shaft and adjacent apartment Show that 2 h non-standard severe design fire doesn t affect shaft Extinguish at 2 h 18

19 Fire Resistance Tests CAN/ULC-S101 tests to confirm fire resistance of floor and wall assemblies Shared shaft wall Apartment ceiling Require 2 hr FRR ANSI/PRG-320 CLT 19

20 Fire Resistance Tests CAN/ULC-S101 20

21 Fire Resistance Tests Floor/ceiling 175 mm 5-ply CLT 90 mm non-combustible glass fibre insulation between 80 mm Z-bars spaced at 600 mm o.c. 1 layer of 5/8 Type X gypsum board on 5/8 RCs Simulated concrete topping on unexposed - 2 layers of cement board 9.4 kpa (50% stress ratio) 21

22 Fire Resistance Tests Image: NRCC Image: NRCC Image: NRCC 2 h 8 min 22

23 Fire Resistance Tests Shared wall assembly 175 mm 5-ply CLT 2 layers 5/8 Type X gypsum board - On both sides during FR test, only exposed side in demonstration - 2 Type S screws at 300 mm o.c. 449 kn/m (50% stress ratio) 23

24 Fire Resistance Tests Image: NRCC Image: NRCC Image: NRCC Image: NRCC 24

25 Fire Resistance Tests 3 h 39 min 25

26 Full-scale Demonstration Funded by Quebec MFFP Coordinated between NRC, FPInnovations, Nordic Engineered Wood Conducted at NRC fire laboratory Almonte, ON 26

27 Structure Construction Mock 3 storey shaft and adjacent apartment Contents: high fuel load No sprinklers worst case A few differences from CAN/ULC-S101 tests 27

28 Shaft Construction 4.6 m x 2.5 m x 9 m high - 3 storeys Pressurized to 12 Pa - Specified in building design 45 min fire door 5-ply CLT unprotected TCs along height Construction adhesive at joints 28

29 Apartment Construction 4.6 m x 5.2 m x 2.7 m high Window 2.5 m x 1.9 m - Max. ventilation conditions 45 min fire door Fire rated caulking at in panel-to-panel joints Floating laminate floor with acoustic underlay installed on concrete floor 29

30 Shared Shaft Wall Construction Shared wall assembly Additional interior wall built inside fire room to achieve sound insulation requirements 19 mm air gap, steel stud wall, 64 mm Roxul Comfortboard CIS, ½ regular gypsum board Common construction adhesive in CLT joints 30

31 Shared Shaft Wall Construction Image: NRCC Image: NRCC Image: NRCC 31

32 Ceiling Construction CLT connection: plywood surface-spline Sealed with construction adhesive CLT supported on glulam ledgers Failure of floor won t affect shaft during fire Encapsulated with 2 layers of 5/8 Type X GB 2 layers ½ cement board fastened to CLT 32

33 Ceiling Construction Induced specified load: 4.74 kpa (0.5L+D) Includes CLT self weight 1.49 kpa Concrete blocks Image: NRCC 33

34 Fuel Load Furnished studio apartment Queen size bed, upholstered chairs, loveseat, dressers, book shelves, wood cribs - Wood cribs: night coffee and dining tables, kitchen cabinets and counters 95 th percentile of residential primary bedroom 790 MJ/m 2 34

35 Fuel Load NRCC 35

36 Instrumentation TC trees in fire room TC tree and optical smoke density meter in shaft 9 TCs in: Shared wall (at various depths) Other side walls: unexposed and behind GB Various floor/ceiling layers 36

37 Demonstration Fire 37

38 Demonstration Fire 38

39 Demonstration Fire VIDEO 39

40 loveseat ignition Image: NRCC 40

41 Image: NRCC 41

42 Image: NRCC 42

43 flashover Image: NRCC 43

44 clean air entered on RHS and lower potion of window Image: NRCC 44

45 peak temp o C Image: NRCC 45

46 ceiling GB falling Image: NRCC Image: NRCC 46

47 fire door red hot, UF and mattress consumed Image: NRCC Image: NRCC 47

48 steel ceiling components fell CLT ceiling fully involved Image: NRCC 48

49 intensity visibility face GB gone on shared wall Image: NRCC 49

50 1 st ply falling off more vigorous burning fire reducing in size Image: NRCC Image: NRCC 50

51 no fire plume out window Image: NRCC 51

52 CLT 2 nd layer falling off Image: NRCC 52

53 2 layers of GB sill on walls Roxul and studs still in place Extinguished at 2 h Image: NRCC Image: NRCC 53

54 Temperatures More severe than CAN/ULC-S101 Especially during first 30 min Peaked at 10 min in room 30 min Declining temperatures TC trees fell 70+ min all temperatures decreasing 54

55 Temperatures NRCC 55

56 Condition of Apartment After Fire Ceiling All materials attached to CLT had fallen 1 st and 2 nd layer charred Apartment Walls GB remained in place 1 st ply lightly charred Shared Wall Acoustic wall still in place Minimal surface charring of CLT 56

57 Ceiling Assembly First two CLT plys were charred Second layer in place, fell off from hose - 3 rd ply exposed after test 3 rd ply charred in some places, but mostly unaffected Unexposed side: temp. all below 140 o C Δ temp 6 o C, one 46 o C - Well within CAN/ULC-S101 limits 57

58 Ceiling Assembly Between insulation and CLT NRCC 58

59 Ceiling Assembly Unexposed side NRCC 59

60 Apartment Walls (other than shaft wall) 2 layers of GB remained in place 1 st ply CLT surface evidence of charring Behind GB ~300 o C at 60 min - Temps <500 o C - CLT not involved in flaming combustion - CLT did not contribute to fire growth 60

61 Apartment Walls Between base layer GB and CLT NRCC 61

62 Apartment Walls Unexposed side of CLT NRCC 62

63 Shared Wall 1 st layer of ½ regular GB fell off Acoustic wall with Roxul insulation still in place 2 layers of ⅝ Type X GB still in place Some GB fell during extinguishment Surface of CLT lightly charred near door 5 mm char Temperatures at CLT below 400 o C Little effect on structural resistance of CLT 63

64 Shared Wall Between GB and CLT NRCC 64

65 Shared Wall Image: NRCC 65

66 Shared Wall Image: NRCC Image: NRCC 66

67 Inside Shaft No smoke or heat penetration No effect on evacuation or tenability No apparent structural impact 67

68 Inside Shaft Unexposed CLT surface NO TEMPERATURE RISE ON UNEXPOSED CLT SURFACE 68

69 Inside Shaft TCs along height NO TEMPERATURE RISE IN THE SHAFT 69

70 Inside Shaft Optical density/visibility NO CHANGE IN OPTICAL DENSITY (no smoke leakage) 70

71 Encapsulation Protection of combustible elements Delay effects of fire on CLT Limit contribution to fire Surface average Δ250 o C or point Δ 270 o C Wood chars at 300 o C Encapsulation Time During Test Ceiling 15.2 min Apartment walls 56.9 min Shaft Wall 91 min 71

72 Conclusions Severe fire challenged the structure for 2 h CLT shaft wall could potentially have lasted another 2 h (including GB) Intensity decreasing after 40 min Reduced charring, potential room burn-out Conditions in shaft were unchanged before, during and after fire in shaft Sprinklers may have extinguished early fire 72

73 Conclusions Demonstrated equivalence to noncombustible construction performance requirements for tall buildings Fire severity, spread of smoke, building integrity 2 h non-standard severe design fire didn t affect shaft Evacuation, fire services 73

74 Conclusions Mass timber construction can safely be used for exit stair construction! Applies to light frame mid-rise buildings Mass timber can be used as an alternative to noncombustible shafts 74

75 Reports Full report available at: ises/rapport-resistance-feu-ang.pdf Osborne, L., Dagenais, C., Full-scale Mass Timber Shaft Demonstration Fire Final Report. FPInnovations Funded by the Ministere des Forets, de la Faune et des Parcs. Gouvernement du Quebec. 75

76 This concludes The American Institute of Architects Continuing Education Systems Course Canadian Wood Council Wood WORKS! Ontario Lindsay Ranger (Osborne), M.A.Sc Scientist, Advanced Building Systems