WoodWorks Webinar “The Wood Products Council” is a Registered Provider with The Decem ber 11, 2013 AmericanInstituteofArchitectsContinuingEducationSystems(AIA/CES). Credit(s) earned on completion of this program will be reported to Glued Laminated Timber – An AIA/CES for AIA members. Certificates of Completion for both AIA Innovative and Versatile members and non-AIA members are available upon request. This p r ogr am i s r egi ster ed wi th AIA/CES foocotr contin uin gpoessoag professional Engineered Wood Composite 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 Product material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Tom Williamson, P.E. Timber Engineering LLC QQp,,uestions related to specific materials, methods, and services will FASCE, FSEI be addressed at the conclusion of this presentation. Retired Vice President, APA FEtiVPAITCFormer Executive VP, AITC
Learning Objectives 1. To illustrate how the flexibility of glulam sizes and shapes can help desigggners meet their most demanding architectural and structural requirements using numerous innovative design examples. Copyright Materials 2. To familiarize designers with how to properly select and specify glulam incorporating relevant industry standards and codes. This presentation is protected by US and 3. To provide design professionals with an overview of key design International Copyright laws. Reproduction, considerations that must be considered to ensure both the structural distribution, display and use of the presentation performance and long-term durability of glulam structures. without written permission of the speaker is 4. To acquaint designers with the unique fire resistive characteristics of prohibited. glulam as it influences the use of wood in commercial building construction. © The Wood Products Council 2012 ~GGnf h GGnGsG{
Glulam = a structural composite of Lumber Laminations lumber and adhesives
Glue Li nes
Natural Wood Characteristics End Joints
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USDA Forest 120 years of use worldwide Products Lab High School in Wisconsin pGhGGn lGl
High degree of engineering
efficiency compared to sawn timber y y c Glulam quen
e MSR lumber e Fr v Visually graded Relati lblumber Material Property Values
kGGzG yGj pGhGGn High degree of engineering efficiency compared to sawn timber Single Lamination Highly efficient use of wood resource from managed forests
Glued Laminated Timber tGsGx G pGhGGn pGpTzGzG High degree of engineering efficiency compared to sawn timber Highly efficient use of wood resource compared to sawn timber Large dimensions possible
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21” x27x 27” x110x 110’ Note multiple pieces positioned side by s ide
These pieces are not typically edge bonded but there is no reduction in stress values when the load is applied perpendicu lar to the wide face |G} GG pGhGGn zGGz High degree of engineering efficiency compared to sawn timber Highly efficient use of wood resource compared to sawn timber Large dimensions possible Virt uall y unli mit ed versatilit y i n shapes and spans
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High degree of engineering efficiency compared to sawn timber Highly efficient use of wood resource compared to sawn timber Large dimensions possible Virtually unlimited versatility in shapes and spans NlhiNatural aesthetic appearance of fd wood nGGl Gm GG pGhGGn zGGn Higggh degree of eng ineering Produced from small dimension lumber harvested efficiency compared to sawn timber from managed and sustainable forests Timber resource utilization Highly efficient use of wood resource optimi zed usi ng a wid e range compared to sawn timber of lumber grades Large dimensions possible Uses a wide variety of species Smaller sections required due Virtually unlimited versatility in shapes to higher strengths and spans Manufacturing involves low Natural aesthetic appearance of wood energy use process Uses low formaldehyde Environmentally friendly (green) emitting adhesives Glulam = Green
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Composite Wood Products Exempt Products End (CARB definition) Material Pre-glue Joint Preparation Layypup Hardwood plywood Structural plywood ( PS1) Bonding Particleboard Structural panels (PS2) Medium density fiberboard Structural composite lumber (ASTM D5456)
Must meet threshold emission Oriented strand board (PS2) Face standards Prefabricated wood I-joists Finish Quality (ASTM D5055) Bonding based on ASTM E1333 Marking Verification Structural glued laminated and Shipping timber (()ANSI A190.1) Curing sGzG| }GsGn
Traditional softwoods Douglas Fir & Southern Pine Other soft wood s Spruce/Pine/Fir and Hem-Fir Naturally durable softwoods Alaska Yellow Cedar Port Orford Cedar Hardwoods Mixed species layups
lTyGsGn zGw nGkG}G Recent changes have resulted in a reduction of Southern pine dimension lumber design values for No. 2 Dense and lower grades Questions raised about this affecting the design values for glulam using Southern pine lblumber Due to the unique grading provisions applied to lumber used in glulam manufacturing these changes have not affected the glulam values Information provided in a white paper on the APA web site nGhGz mGG}GhG
Adhesives used for glulam must meet: Appearance Classifications ASTM D2559 for Exterior-Use Framing – Intended for concealed applications and is typicall y available in 3-1/2” & 5-1/2” widths to match dimensions of 2x4 and 2x6 framing lumber Industrial –Intended for concealed applications or whitfiithere appearance is not of primary importance ASTM D7247 for heat durability Architectural – Used where members are exposed to view and an attractive finish is desired Premium – Available only as a custom order where appearance is of primary importance Strength is not impacted by appearance classifications
nGtGz x G{ huzpGhX`WUXTYWXY Specifies product qualification and quality assurance requirements Third-party inspection by an approved agency is required on an on-going basis APA Building codes require all glulam to bear a trademark UNBALANCED ARCH 24F-V3 APA Y117 SP meeting ANSI A190 . 1-2012 PLANT 0000 ANSI A190.1-2012 iGnGkG tG{ j Tfb/ldlitiType of member / load application
Column Truss member
Arch
Simple span beam Cantilever span beam
nGs T| zGnGs Y[mGiGt 302-24 T.L. No. 2D No. 1 Tension No. 2 Compression Zone No. 2 No. 2 Zone Same lumber grade and species used
No. 3 Inner Zone No. 3 Inner Zone throughout Primarily for use in axially loaded No. 2 No. 2 members, such No. 1 Tension No. 1 Tension as columns and 302-24 T.L. Zone 302-24 T.L. Zone truss chords Balanced Unbalanced sGv pGGhGv Y Typical use Design Properties for 24F-V4 layup X-X major axis X Major Axis (X-X) Minor Axis (Y-Y) Fb = 2, 400 psi Fb = 1, 500 psi E = 1,800,000 psi E = 1,600,000 psi X X Y Y
F F E E X bx by x y Y-Y major axis Y Fvx Fvy FcAx FcAy
+ - Fbx Fbx
iGnGkG hz{tGGkZ^Z^ j Analyyptical procedure based Tfb/ldlitiType of member / load application on the growth characteristics of lumber (knots, slope of Determination of allowable design grain and density) stresses / layup selection Standardized analysis procedures to generate all major design properties Allows manufacturers to use comppputer models developed by AITC and APA to optimize available resources to achieve high end performance hz{tGGk^Z[XG mGzGnGiG{
Empirical method based The U.S. has the largest on full-scale glulam combined full scale performance tests in glulam beam database in combinati on with or the world without modeling
8-3/4”x 48”x 64 ft
zGGkGw ukzGzGj ukzGzG 1. Sawn Lumber Gradinggg Agencies Stress Classes Created for Simplicity 2. Species Combinations 3. Section Properties 4. Design Values • Lumber and Timber • Non-North American Sawn Lumber • Structural Glued Laminated Timber • MSR and MEL zGGkG} |zGnGz p GzGVGpjjGj jGz 24F-V8/DF balanced 24F- V4/DF un bal anced ANSI 117 Design Specification Allowable Design V = visually Assigned Stress: graded Wood combination APA ICC-ESR Code 24F = 2,400 psi E = mechanically species number Report 1940 30F = 3,000 psi graded
Glulam standards are referenced in the 30F-E2/SP IBC and IRC codes
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Most common glulam beams are rated at: 5% 302-30 2. 3E Fb = 3000 psi 6 5% No. 1D 2.3E Fb = 2,400 psi E = 1.8 x 10 psi Fv = 300 psi 15% No. 1D 2.0E E = 2,100,000 psi Higher design stresses also possible: Southern Pine Limited to nominal 6 Fb = 3,000 psi E = 2.1 x10 psi 6 inch width or less No. 2M unless manufacturer LVL hybrid qualifies for wider widths 6 Fb = 3, 000 ps i E = 212.1 x10 psi bdflllbased on full scale 15% No. 1D 2.0E testing Note: E values for glulam are apparent E and include allowance for 5% No. 1D 2.3E shear d efl ecti on t o si mplif y d efl ecti on cal cul ati ons. Oth er prod uct s may publish shear free E values which are 5 % higher. 5% 302-30 2.3E s}sGo GnGGs}sG iGnGkG vGs j Full length with no LVL Laminations Tfb/ldlitiType of member / load application finger joints required Top and Bottom LVL has greater Determination of allowable design tensile strength stresses / layup selection compared to lumber Structural analysis 30F-2.1E stress level achieved Direct substitute for products such as LVL and PSL
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1 General Requirements for Building Design 2 Design Values for Structural Members 3 Design Provisions and Equations 4 Sawn Lumber Includes both 5 Structural Glued Laminated Timber 6 Round Timber Poles and Piles Allowable Stress 7 Prefabricated Wood I-Joists Desigg(n (ASD) and 8SttlC8 Structural Compos itLbite Lumber 9 Wood Structural Panels Load and 10 Mechanical Connections 11 Dowel-Type Fasteners Resistance Factor 12 Split Ring and Shear Plate Connectors 13 Timber Rivets Design (LRFD) 14 Shear Walls and Diaphragms 15 Special Loading Conditions 16 Fire Design of Wood Members symkGUGhzkG hGnGkGy
LRFD and ASD presentation formats are different Example equations for bending moment: AITC “Timber Construction Simple span beam with uniform load Manual”
ASD LRFD Applied stress Allowable stress McGraw-Hill “APA Engineered Factored Load Factored f F ’ b b Resistance Wood Handbook” M / Sx FbCD Mu Mn’
Mu Fb KF OISx McGraw-Hill “Wood Engineering End result will be approximately the same member size for glulam and Construction Handbook”
iGnGkG hGGiGkG} j F ’ =F= F C C C (C or C )C) C Tfb/ldlitiType of member / load application b b D M t L V C F ’ = F C C C Determination of allowable design v v D M t stresses / layup selection E’ = E CM Ct
Structural analysis • CD = load duration factor • C = wet-use factor (16% or greater) Stress modification factors M • Ct = temperature factor
• CL = beam stability factor
• CV = volume effect factor
• CC = curvature factor jGmG }GmG iGz iGz C =1= 1- 2000 (t/R)2 C 1/x 1/x 1/x 21 12 5.125 t = thickness of lamination (in) C = 1.0 R = radius of curvature of the lamination (in) v L d b Rrec = 27’- 6” for all species with t = 1.5” Rrec =9= 9’- 4” for Western species with t = 0 .75 ” Rrec = 7’- 0” for Southern pine with t = 0.75” L = beam length (ft) d = beam depp(th (inches) Tighter radius can be achieved by using thinner b = beam width (inches) laminations but t/R cannot exceed 1/100 for S.P x = 20 for Southern pine and 1/125 for other softwood species x = 10 for all other species
pGG}GlGm iGnGkG j Tfb/ldlitiType of member / load application Determination of allowable design stresses / layup selection Stress modification factors Structural analysis Size: 8 -3/4” x72x 72” x 100’
Cv = 0.82 for S.P. Special design provisions Cv = 0.68 for other species Fb’ = 2400 x .68 = 1632 psi for DF { GnGiGs {GGˈ{vwˉGz G|Gs 24F-V4 DF Unbalanced (12 Lamination Example)
2 - L2 Dense Grade Outer Comp. Lams 1 - L2 Grade Inner Comp. Lam
6 - L3 G rad e C ore L ams
1 - L2 Grade Inner Tension Lam 1- L1 Grade Inner Tension Lam 1- 302-24 Outer Tension Lam Trademark
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Based on full-size beam tests conducted at APA, the “upside down” bending stress is 75% of the normal bending capacity z Gj z Gj
Glulam can be manufactured with camber Camber can be specified in inches or as a radius of curvature to offset the anticipated dead load deflection Very important for long span members
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12-1/4” x 84” 140 ft. clear span Camber = 8”
Spans of 80-100 feet or more are common for glllulam EWS S560F uGGkG lGuGGn
Problem Solution Tension perpendicular Provide full end grain bearing to grain stresses induced
Note end notch limitation for glulam
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Strength reduction = 1.5 x hole diameter/beam width
Example: • 6-3/4” beam width • 1” diameter vertical hole Reduction = (1.5 x 1.0/6.75) Reduction = 0.22 Beam has 78% of original strength lGG}Go uGGkG
3” ho le OOP Hor izont al H ol e D r illing in 6-3/4” wide glulam
Only 1/3rd of strength retitaine d
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Tfb/ldlitiType of member / load application Determination of allowable design stresses / layup selection Stress modification factors Structural analysis Special design provisions Connection design /detailing k GGsG{G jGk w The NDS provides nominal Strategies for durable glulam construction lateral and withdrawal values for dowel type connectors and Keep glulam dry specialty connectors such as Focus on design and construction details shear plates, split rings and timber rivets Focus on moisture management Allowable = nominal x Use appropriate preservative treatments when adjustment factors exposed to the elements or Adjustment factors account for a Specify naturally durable and decay resistive wide range of different end use wood species applications All design information is Numerous examples of glulam structures 50-100 applicable to glulam years old worldwide
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2009 75 years of 1934 continuous use nGjGi wGiGGT XW\GUG
wGiGˀ XYWGUG nGhGo GiGG zGkGT j nGhGo GiG nGnGi lGkGT t uGjG
Erected in 1973 10-3/4” x 60” x 80 ft 40 years of center span gidirders in-service use
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Original 2009 installation 1968 Over 45 years of in-service 1988 use Some in service since 1970 wG{GGn zGwG{G
U.S. Standards APA-EWS S580C American Wood Protection Association (AWPA U1-13) UC1 Interior, dry Insects UC2 Interior, wet Decay and insects UC3 Exterior, above ground Decay and insects UC4 Ground contact Decay and insects UC5 Salt water Salt water organisms American Association of State Highway and Transportation Officials (AASHTO) Above ground Ground contact, fresh water Ground contact, salt water U.S. building codes require treatment of exposed glulam Applicable treatments are a function of species and whether treatment is before or after gluing
hGGjGOhjP u GkGzG zGtSGjhGyGj Port Orford Cedar 22F-1.8E Alaska Yellow Cedar 20F-1.5E Western Red Cedar 16F-13E1.3E California Redwood 16F-1.1E }GuGyGjG z Gp sGhG|GhjGn
Temperature – not of major importance 650, 000 sq. ft. HiditdHumidity and moi itsture – can be a 15 acres major concern exposed end grain contact with concrete or masonry moisture entrapment ambient conditions / dimensional changes
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Issue: direct water ingress into the wood Issue: direct water ingress End caps and Water is absorbed flashing used rappyidly throu gh Minimal roof overhang, no end Re-direct the water flow the end grain of caps andflhidd no flashing used around the ends of the wood glulam Project is in Palm UtittdUse preservative treated Springs, CA glulam or durable species when ex posed to t he Heavy checking weather and deterioration nGiG lGnGl jGGt
Minimal roof overhang Prevent contact with No flashing Checking occurred in 1st year Note steel concrete or masonry Decay may follow bibearing UbiUse bearing pl ltate plate under glulam member Maintain minimum of ½” air gap at end Note gap Roof overhang at end End grain flashing NftNo future mo itisture re ltdlated problems anticipated
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Grout used at bearing No air space Problem No provision for moisture to escape Potential for decay to develop Adding a drainage slot at bottom Need 1/2 ” air gap between would alleviate wood and masonry problem hGiGGz hGiGGz
Exposed glulam NtNote flhiflashing on A-frame with no top of glulam flashing and a closed shoe Closely spaced fasteners No provision such as weep hlholes or sltlots t o Note open shoe allow moisture to allowing water to drain drain After 25 years in service
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Ends covered
Closed shoe lGGtGj nGiGlGiG Gj
Glulam ¼” Sawn timber ¾”
24” 15-1/4” Cracks developing
Note bearing angle Green 8% and slight gap at wood 12% 8%
iGGi nGiGlGi zTjGr w Solution: allow shrinkage to occur without inducing tension perp stresses by ? keeppging bolts at bottom or use slotted holes Slotted holes lGGtG lGGj
Seasoning checking Is it of structural concern? Side checks End checks
Bottom glue line check
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Checking is a natural phenomena associated with moisture cycling of wood Guidelines established for Delamination is a deterioration of the glue bond what size checks are OK when exposed to moisture without an engineering analysis The r equir em en t f or usin g w et-use (durab le) adhesives and ongoing quality assurance Published in an Owners during the manufacture of glulam eliminates Guide to Checking delamination as a concern One of the industry’s Checking can be unsightly and be a visual most widely distributed concern but is seldom of structural significance publications sGsGGlGk jGGnGGmG GsGsGnGzG
Keep glulam dry whenever possible Wood is an excellent Account for moisture effects heat insulator High moistu re = mold, decay, insect attack Develops a char layer Protect from direct exposure to elements after fire exposure Use preservative treatments Self-extinguishing Use naturally durable species after fire source 10-3/4 x 16-1/2 Desigggpn connections for long term performance removed Allow for movement due to moisture changes Retains significant Design to avoid moisture entrapment residual strength after Avoid direct contact with masonry and concrete being exposed to fire
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Char rate = 1/40” per minute or 1-1/2” per hour pijGt mGyGGnG zG^YYU]UZ
TtdfiTwo accepted fire rating methods Empirical calculation protocol recognized in the U . S. Based on extensive testing in the IBC Empirical Method U.S. and other countries using the NDS Mechanics Based ASTM E119 (ISO 834) fire test Model protocol
FRT Beams – 3 or 4 s ides expose d Columns – 3 or 4 sides exposed Flame spread coatings One hour ratings can be calculated
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Beams exposed on 3 sides t = 2.54ZB [ 4 – B/D ] Chapter 16 Beams exposed on 4 sides Mechanics based t = 2.54ZB [ 4 – 2B/D ] model B = beam w idth SpportedbSupported by D = beam depth empirical data t = fire resistance in minutes 1, 1-1/2 and 2 hour Z = load compensation factor ratings can be = applidllied load d/d / desi gn capacit y determined YWW\GukzGt mGyGn
t Eeff 1.8 in./hr 1.2En 1hr1 hr Eeff (45.7 mm/h r) t 0.187 1.58 in./hr 2hr2 hr (40.1 mm/hr) Where:
Eeff = Effective char rate (in. /hr), adjusted for exposure time, t
En = Nominal char rate (1.5 in./hr) t = Exposure time (hr)
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24F-V4 DF Unbalanced (12 Lamination Example) Glulam stock beams often 2 - L2 Dense Grade Outer Comp. Lams 1 - L2 Grade Inner Comp. Lam used in residential and 6 - L3 G rad e C ore L ams light commerci al
1 - L2 Grade Inner Tension Lam construction 1- L1 Grade Inner Tension Lam 1- 302-24 Outer Tension Lam
For 1 -hour fire rated beam: substitute additional 302-24 tension lam for core lam Glulam Beams Stored Stock Beam Manufacturing at Dis tr ibuti on Y ard s
Manufactured in longgg,yg lengths, varying cross-sections, usually unbalanced, minimal camber
Glulam Beams Shipped to Job Site Stock Beams - Typical Uses
Roof Beams Proper handling
Proppger storage Stock Beams - Typical Uses Stock Beams - Typical Uses
Garage Door Headers Simple Span Floor Beams
Stock Beams – Typical Uses Stock Beams - Typical Uses
Continuous Span Floor Beams IJC Beams and Headers I-Joist Compatible (IJC) Glulam Column Applications
9-1/2", 11-7/8", 14" & 16" depths 3-1/2", 5-1/2" &7& 7" widths Camber: zero, 3500 ft or 5000 ft radius Lay-up combinations • Typically 24F - 1.8E Unbalanced DF & SP • 30F - 2.1E may also be available in some markets Tall wall framing with glulam columns
Stock Beams – Light Commercial Stock Beams – Light Commercial Finn Hill Jr. High Custom Beams and Arches Kir klan d, WA
Bullitt Center Oceans Exhibit – Indianapolis Zoo Sea ttle, WA Autzen Field USDA Centennial Research Center UiUnivers ity o fOf Oregon MdiMadison, WI
Light Rail Transit Center Cathedral of Light Vancouver, B. C. OkldCAOakland, CA Airport Terminal Terminal Two Vic tor ia, B. C. RlihDRaleigh Dur ham Airpor t
Kingsway Bridge 2010 Olympic Skating Oval BbBCBurnaby, B.C. Ric hmon d, B. C. Art Gallery Chicago Bears TtOtiToronto, Ontario WltWalter Pay ton Prac tice Fac ilitility
Chemical Storage Facility LeMay America’s Car Museum PtldORPortland, OR Tacoma, WA Twin Rink Ice Arena Chicago’s Lincoln Park Zoo AhiCAAnaheim, CA. SthPdPiliSouth Pond Pavilion
AT&T PARK in San Francisco “Life Cycle” Alaska Yellow Cedar Wood Products
This is all glulam
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Shipped fully assembled Additional Glulam Information Qti?Questions? www.apawood.org This concludesThe American InstituteofArchitectsContinuing Glulam Product Guide EducationSystemsCourse Case Studies ThilNtTechnical Notes Tom Williamson,P .E . T.WilliamsonͲ TimberEngineeringLLC Beam and Column Tables tomwilliamson@live. com Manufacturer Product Reports AdAnd muc h more