Glulam Webinar compressed - WoodWorks

Wood Products Council Webinar O b 27 2010October 27, 2010

Glued Laminated Timber – AnGlued Laminated Timber An Innovative and Versatile Engineered Wood ProductEngineered Wood Product

Tom Williamson, P.E.Consulting EngineerRetired Vice President, APAPast Executive VP, AITC,

Copyright MaterialsCopyright Materials

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di ib i di l d f h idistribution, display and use of the presentation without written permission of the speaker is

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© Wood Products Council

Wood Products Council is a Registered Provider with The American Institute of Architects Continuing Education Systems. Credit earned on completion of this program will be reported to CES Records for AIA members. Certificates of Completion for non-AIA members are available on request.

This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or y ppendorsement 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 specificin any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.

Learning ObjectivesLearning Objectives

#1 To illustrate how the flexibility of glulam sizes and shapes y g pcan help designers meet their most demanding architectural and structural requirements.

#2 To familiarize designers with how to select and specify#2 To familiarize designers with how to select and specify glulam incorporating new technology and standards changes that have occurred in recent years to expand and enhance the use of glulam as an engineering materialthe use of glulam as an engineering material.

#3 To provide design professionals with an overview of key design considerations that must be considered to ensure b th th t t l f d l t d bilit fboth the structural performance and long-term durability of glulam structures.

#4 To acquaint designers with the unique fire resistive characteristics of glulam as it influences the use of wood in commercial building construction.

What is Glulam?What is Glulam?

Glulam = a structural composite of plumber and adhesives

Anatomy of Glued Laminated TimberAnatomy of Glued Laminated Timber

Lumber LaminationsLumber Laminations

Gl LiGlue Lines

Natural WoodEnd Joints

Natural WoodCharacteristics

Glulam – One of the Original Glued E i d W d C iEngineered Wood Composites

Over 115 years of use worldwide

“Life Cycle”Wood Products“Life Cycle”

Wood ProductsWood ProductsWood Products

Inherent Benefits of GlulamInherent Benefits of Glulam

High degree of engineering High degree of engineering efficiency compared to sawn timber

Engineering EfficiencyEngineering Efficiency

cyy

MSR

Glulam

eque

nc

MSRlumber

ve F

re

Visually graded l bR

elat

iv

Material Property Valueslumber

Dispersal of Strength R d i Ch i iReducing Characteristics

Single LaminationSingle Lamination

Glued Laminated Timber


High degree of engineering High degree of engineering efficiency compared to sawn timber Highly efficient use of wood resource from managed forests g

Matching Lumber Quality toInduced In-Service Stresses


High degree of engineering High degree of engineering efficiency compared to sawn timber Highly efficient use of wood resource compared to sawn timberp Large dimensions possible

Spans of 100 feet or greaterSpans of 100 feet or greater Oceans Exhibit – Indianapolis ZooOceans Exhibit Indianapolis Zoo

10-3/4” x 72”10 3/4 x 72115 ft. clear span

Church in Louisville KYChurch in Louisville, KY

12-1/4” x 84”12 1/4 x 84140 ft. clear span


High degree of engineering High degree of engineering efficiency compared to sawn timber Highly efficient use of wood resource compared to sawn timberp Large dimensions possible

Vi t ll li it d tilit i Virtually unlimited versatility in shapes and spans

Unmatched Versatility of Sh d SShapes and Spans Inherent Benefits of GlulamInherent Benefits of Glulam

High degree of engineering efficiency compared to sawn timber Highly efficient use of wood resource compared to sawn timbercompared to sawn timber Large dimensions possible Virtually unlimited versatility in shapes Virtually unlimited versatility in shapes and spans

N l h i f d Natural aesthetic appearance of wood

Natural Aesthetics of GlulamNatural Aesthetics of Glulam Inherent Benefits of GlulamInherent Benefits of Glulam

High degree of engineeringHigh degree of engineering efficiency compared to sawn timber Highly efficient use of wood resource Highly efficient use of wood resource compared to sawn timber

L di i ibl Large dimensions possible Virtually unlimited versatility in shapes and spans Natural aesthetic appearance of woodpp Environmentally friendly (green)

Environmentally Friendly (Green)Environmentally Friendly (Green)

Produced from small dimension lumberProduced from small dimension lumber harvested from managed and sustainable forestsTimber resource utilization optimized using a

wide range of lumber gradesUses a wide variety of species Smaller sections required due to higher q g

strengthsManufacturing involves low energy use process Uses low formaldehyde emitting adhesives

Formaldehyde: CARBFormaldehyde CARB

Composite Wood Products

Hardwood plywood

Exempt Products(CARB definition)

Structural plywood (PS1) Hardwood plywood ParticleboardMedium density fiberboard

Structural plywood (PS1) Structural panels (PS2) Structural composite lumber

(ASTM D5456)

Must meet threshold emission standards

(ASTM D5456) Oriented strand board (PS2) Prefabricated wood I-joists

based on ASTM E1333 (ASTM D5055)

Structural glued laminated timber (ANSI A190.1)( )

Glulam Manufacturing StandardANSI/AITC A190 1ANSI/AITC A190.1

Glulam Manufacturing ProcessGlulam Manufacturing Process

Lumber Species UsedLumber Species Used

Traditional softwoods Traditional softwoodsDouglas Fir & Southern Pine

Oth ft d Other softwoodsSpruce/Pine/Fir and Hem-Fir

Naturally durable softwoodsAlaska Yellow CedarPort Orford Cedar

Hardwoods Mixed species layups

Visual Lumber GradesVisual Lumber Grades

E-Rated Lumber GradesE Rated Lumber Grades Lumber Grading Checked in Millg

Checking visual grades

Verifying E-rating

Glulam Adhesive SpecificationsGlulam Adhesive Specifications

Adhesives used for glulam must meet:Adhesives used for glulam must meet: ASTM D2559 for Exterior-Use

ASTM D7247 for heat durability

Structural End JointStructural End Joint

Horizontal Finger JointHorizontal Finger JointHorizontal Finger Joint Horizontal Finger Joint

Adhesive beingappliedpp

End joint adhesiveis typically ais typically amelamine or phenol resorcinol

Finger JointingU i g RF C ri gUsing RF Curing

In line bending proof loaderIn-line bending proof loaderused to monitor end joint quality

Pre-Glue LayupPre Glue Layup

Long length laminations positioned bygrade All North American and international

glulam standards require positioning g q p gof laminations by grade Lumber quality is a key to controllingLumber quality is a key to controlling

glulam member performance

Unbalanced LayupUnbalanced Layup

Unequal capacity Unequal capacity in positive and negative bending

Primarily for use in simple beams or shortor short cantilevers

Requires 5%Requires 5% tension lams on the bottom of the beambeam

Balanced LayupBalanced Layup

E l it i Equal capacity in both positive and negative bendingg g

Primarily for use in continuous beams or long cantilevers

Requires 5% Requires 5% tension lams on top and bottom of beam

Single Grade LayupSingle Grade Layup

Same lumber grade andgrade and species used throughoutg Primarily for use

in axially loaded ymembers, such as columns and truss chords

Pre-Glue LayupPre Glue Layup

Lumber is often color coded by grade

Face BondingFace Bonding

Clamping and CuringClamping and Curing Large Cross Sections Are PossibleLarge Cross Sections Are Possible

21” x 27” x 110’21 x 27 x 110Note multiplepieces positionedpieces positionedside by side

No reduction inNo reduction in stress values evenif pieces are notedge bonded and load is appliedperpendicular toperpendicular tothe wide face

Fabrication & FinishingFabrication & Finishing Fabrication and FinishingFabrication and Finishing

Shaping

Planing

Shaping

PlaningSawing

Finishing for Visual Appearance

Appearance Classifications

Finishing for Visual Appearance

Appearance Classifications Framing – Intended for concealed applications and is

typically available in 3-1/2” & 5-1/2” widths to match yp ydimensions of 2x4 and 2x6 framing lumber

Industrial – Intended for concealed applications or h i t f i i twhere appearance is not of primary importance

Architectural – Used where members are exposed to view and an attractive finish is desiredview 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

Quality Assurance VerificationQuality Assurance Verification

Face bond integrityShear strength & W.F. Durability/delamination End joint integrityj g y

Full scale tension test usedStrength and W.F. evaluatedStrength and W.F. evaluated Appearance characteristics

Finished dimensions & shape Finished dimensions & shape

Quality TrademarksQuality Trademarks Protection For Shipping & HandlingProtection For Shipping & Handling

Protection for Shipping and StorageProtection for Shipping and Storage Basic Glulam Design Considerations

T f b / l d li ti Type of member / load application Determination of allowable design g

stresses / layup selection Stress modification factors Stress modification factors Structural analysis Special design provisions Connection design /detailing Connection design /detailing

Member TypeMember Type

ColumnColumn Truss member

Simple span beam Cantilever span beam

Loading OrientationsLoading Orientations

Y

XTypical useX-X major axis

Y YX X Y Y

XXY Y-Y major axis Fbx ≠ Fby Ex ≠ Ey

Fvx ≠ Fvy Fcx ≠ Fcy

Fbx+ ≠ Fbx

-

Importance of Axis OrientationImportance of Axis Orientation

Design Properties for 24F-V4 layupMajor Axis (X-X) Minor Axis (Y-Y)F 2 400 i F 1 500 iFb = 2,400 psi Fb = 1,500 psi E = 1,800,000 psi E = 1,600,000 psi

Basic Glulam Design Considerations



US Glulam StandardsD l t f D i V lDevelopment of Design Values

D i l d i d i dDesign values are derived in accordance with:

ASTM D3737ASTM D3737

Based on the growthBased on the growth characteristics of lumber (knots, slope of grain and d it )density) Standardized analysis

procedures to generate all major design properties Allows manufacturers to

use computer modelsuse computer models developed by AITC and APA to optimize available resources to achieve highresources to achieve high end performance

ASTM D7341ASTM D7341

Based on full-scaleBased on full scale glulam performance tests in combination with or without modeling

Full Scale Glulam Beam TestsFull Scale Glulam Beam Tests

The U.S. has the largest combined full scale glulam beam database inglulam beam database in the world

Horizontal Shear Values for GlulamHorizontal Shear Values for Glulam

P/2 P/2

6" Minimum

h

2h Minimum 2h Minimum

Species 1997 NDS 2005 NDSP/2P/2

Species 1997 NDS 2005 NDSDF 190 265SP 240 300SP 240 300

Hem-Fir 155 215

Sources of Design Properties

1. Sawn Lumber Grading Agencies

2005 NDS Supplement g g

2. Species Combinations3. Section Properties4. Design Values

• Lumber and Timber• Lumber and Timber• Non-North American Sawn Lumber• Structural Glued Laminated Timber• MSR and MEL

NDS Stress Classes

Stress Classes Created for Simplicity

NDS Stress Classes

Stress Classes Created for Simplicity

Sources of Design Properties I d S d d / ICC C dIndustry Standards / ICC Codes

AITC 117 Design SpecificationSpecification

APA ICC-ESR Code Report 1940

Glulam standards Glulam standards are referenced in the IBC and IRC codesIBC and IRC codes

Glulam Design StressesGlulam Design Stresses

Note: E values for glulam are apparent E and include allowancefor shear deflection to simplify deflection calculations

E-Rated Southern Pine Layup30F 2 1E S G d30F – 2.1E Stress Grade

2 3E2.3ENo. 1DNo. 2D

No. 2M

No. 2DNo. 1D2.3E

LVL Hybrid Glulam with LVL LVL Hybrid Glulam with LVL Outer LaminationsOuter Laminations

F ll l th ith LVL Laminations Full length with nofinger joints required

LVL Laminations

LVL has greater tensile strength

d t l bcompared to lumber

30F-2.1E stress level achieved

Direct substitute for many SCL products

LVL “Hybrid” GlulamLVL “Hybrid” GlulamLVL Hybrid GlulamLVL Hybrid Glulam

Tested at APA Research Center 30F - 2.1E stress grade Approved for use in the U.S.

by ICC ESR code reportsby ICC-ESR code reports Limited to depths of 30” or less

FRP Reinforced GlulamFRP Reinforced Glulam

Fiberglass

Fiber Reinforced Polymers (FRP)FiberglassCarbonKevlar

Thin Layer of FRP Kevlar

Otherof FRP

Behavior of FRP Reinforced GlulamBehavior of FRP Reinforced Glulam

CompressionCompression

TensionLower grades of lumber adequate to resist compression forces

Very high grades of lumber needed to resist tension forcesFRP reinforcement acts similar to rebar used in reinforced concrete

Tension Reinforcement

22,000

16 000

18,000

20,000 3% GRP:MOR=9,465DUCT=3 1 1% GRP:

12,000

14,000

16,000 DUCT=3.1 MOR=7,229 DUCT=1.7

6,000

8,000

10,000

CONTROL: 5 1/8”x12”x21’

0

2,000

4,000 MOR=4,013DUCTL=1

5-1/8”x12”x21’

00 1 2 3 4 5 6 7 8 9 10

FRP Reinforced GlulamFRP Reinforced Glulam

E l f i t d iExample of introducing the FRP in the first glueline – barely discernable

Bending stresses of 30F 32F 34F or 36F30F, 32F, 34F or 36F can be achieved

Optimizing Strength with FRPOptimizing Strength with FRP

FRP on the bottom face of the beam

ICC-ES AC 280ICC ES AC 280

ASTM D7199ASTM D7199University of Maine

RELAM C M d lRELAM Computer Model

AASHTO FRP Reinforced GlulamS Cl B d RELAMStress Classes Based on RELAM

St Cl Fb * MOEStress Class Fb * MOE

30F-2.0E 3000 2,000,00032F-2.1E 3200 2,100,000, ,34F-2.1E 3400 2,100,00036F 2 2E 3600 2 200 00036F-2.2E 3600 2,200,000

* Volume Effect = 1 0 for bending stresses when* Volume Effect = 1.0 for bending stresses when at least 1.0% of FRP is used

APA Test Program of FRP GlulamAPA Test Program of FRP Glulam

FRP Test Program underway to be used as the FRP Test Program underway to be used as thebasis for APA obtaining an ICC-ESR code report Based on AC 280 and ASTM 7199 Based on AC 280 and ASTM 7199 Based on University of Maine RELAM

computer model with FRP on tension face ofcomputer model with FRP on tension face of the beam Uses lumber properties, FJ strengthUses lumber properties, FJ strength

and FRP characteristics as inputs Completion of this study will make this p y

technology more readily available

Western Washington UniversityWestern Washington University

Small GymSmall Gym12-1/4” x 70” x 78 ft. 10-3/4” x 57” x 78 ft.

Natatorium12 1/4” 81” 91 ft12-1/4” x 81” x 91 ft. 10-3/4” x 64-1/2” x 91 ft.

Western Washington UniversityWestern Washington University

Main GymMain Gym14-1/4” x 90” x 106 ft. 10-3/4” x 75” x 106 ft.

Cost savings for theFRP glulam beamsFRP glulam beamswas $22,000



stresses / layup selection Structural analysis Structural analysis Stress modification factors Special design provisions Connection design /detailing Connection design /detailing

Glulam Design: 2005 NDSGlulam Design: 2005 NDS

20051 General Requirements for Building Design2 Design Values for Structural Members3 Design Provisions and Equations4 Sawn Lumber4 Sawn Lumber5 Structural Glued Laminated Timber6 Round Timber Poles and Piles7 Prefabricated Wood I-Joists8 St t l C it L b8 Structural Composite Lumber9 Wood Structural Panels10 Mechanical Connections11 Dowel-Type Fastenersyp12 Split Ring and Shear Plate Connectors13 Timber Rivets14 Shear Walls and Diaphragms15 Special Loading Conditions15 Special Loading Conditions16 Fire Design of Wood Members

Additional Glulam Design Referencesg

AITC “Timber ConstructionAITC Timber Construction Manual”

McGraw-Hill “APA Engineered gWood Handbook”

McGraw-Hill “Wood Engineering and Construction Handbook”

Glulam Design: 2005 NDSGlulam Design 2005 NDS

Includes both Allowable Stress Design (ASD) and g ( )Load and Resistance Factor Design (LRFD)

LRFD vs. ASDLRFD vs. ASD

LRFD and ASD presentation formats are differentExample equations for bending moment:

Simple span beam with uniform load

ASDApplied stress ≤ Allowable stress

LRFDF d L d F d

ppfb ≤ Fb’

M / Sx ≤ FbCD

Factored Load ≤ Factored Resistance

Mu ≤ Mn’

Mu ≤ Fb KF Sx

End result will be approximatelythe same member size for glulam



stresses / layup selection Structural analysis Structural analysis Stress modification factors Special design provisions Connection design /detailing Connection design /detailing

Adjustments for Basic Design ValuesAdjustments for Basic Design Values

F ’ = F C C C (C or C ) CFb’ = Fb CD CM Ct (CL or CV) CC

Fv’ = Fv CD CM Ct

E’ = E CM Ct

C l d d ti f t• CD = load duration factor• CM = wet-use factor (16% or greater)• C = temperature factor• Ct = temperature factor• CL = beam stability factor• CV = volume effect factorCV volume effect factor• CC = curvature factor

Curvature Factor forB di S hBending Strength

C = 1 2000 (t/R)2

t = thickness of lamination (in)R di f t f th l i ti (i )

CC = 1- 2000 (t/R)2

R = radius of curvature of the lamination (in)

R = 27’- 6” for all species with t = 1 5”Rrec = 27 - 6 for all species with t = 1.5Rrec = 9’- 4” for Western species with t = 0.75” Rrec = 7’- 0” for Southern pine with t = 0.75”rec p

Tighter radius can be achieved by using thinner l i ti b t t/R t d 1/100 f S Plaminations but t/R cannot exceed 1/100 for S.P and 1/125 for other softwood species

Volume Factor forB di S hBending Strength

C = ≤ 1.01/x

121/x21 5.125

1/x

Cv ≤ 1.0dL b

L = beam length (ft)d = beam depth (inches)p ( )b = beam width (inches)x = 20 for Southern pinex = 10 for all other species

Impact of Volume Effect FactorImpact of Volume Effect Factor

Size: 8-3/4” x 72” x 100’Size: 8-3/4 x 72 x 100Cv = 0.82 for S.P.Cv = 0.68 for other speciesv pFb’ = 2400 x .82 = 1968 psi for S.P.




Glulam Layups

Unbalanced Layup

Glulam Layups

Medium Grade Inner Compression LamHigh Strength Outer Compression Lams

Unbalanced Layup

Lower Grade Inner Lams

Medium Grade Inner Compression Lam

Medium Grade Inner Compression LamHigh Strength Outer Tension LamsMedium Grade Inner Compression Lam

Note the “TOP” Stampf U b l d Lfor Unbalanced Layup

Improper InstallationImproper Installation

Unbalanced Layups“U id D ” B di S“Upside Down” Bending Stresses

Based on full-size beam testsbeam tests conducted at APA, the “upside down”the “upside down” bending stress is 75% of the normal75% of the normal bending capacity

Specifying CamberSpecifying Camber

Glulam can be manufactured with camberGlulam can be manufactured with camberto offset the anticipated dead load deflection Very important for long span members

Specifying CamberSpecifying Camber

Camber can be specified in inches or as a radius of curvatureCamber can be specified in inches or as a radius of curvature

Importance of CamberImportance of Camber

C b b 1”Camber can be < 1”or > 12” dependingon span and loadsp

Field Notching and Drilling of Glued L i d Ti b BLaminated Timber Beams

Notching and DrillingNotching and Drilling

Problem SolutionTension perpendicular

Provide full end grain bearingto grain stresses induced

Provide full end grain bearing

Possible Reinforcement f E d N h i Gl lfor an End Notch in Glulam

Note end notch limitation for glulam


T d t i idTapered cut on compression side

Effects of Vertical Holes

Strength reduction = 1.5 x hole diameter/beam width

Example:• 6 3/4” beam width• 6-3/4 beam width• 1” diameter vertical holeReduction = (1.5 x 1.0/6.75)Reduction = 0.22Beam has 78% of original strength

Effects of Vertical HolesEffects of Vertical Holes

OOPOOP

Oops


H i t l H l D illiHorizontal Hole Drilling

Basic Glulam Design ConceptsBasic Glulam Design Concepts



Glulam ConnectionsGlulam Connections Connection DesignConnection Design

The NDS design providesThe NDS design provides nominal lateral and withdrawal values for dowel type connectors (nails screwsconnectors (nails, screws, bolts) and specialty connectors such as shear plates, split rings and timber rivetsand timber rivets

Allowable = nominal x adjustment factors

Adjustment factors account for a wide range of different end use applicationsapplications

All applicable to glulam

Basic Wood Connection ConceptsBasic Wood Connection Concepts

Wood cannot resist tension perpendicular to grain stresses – no published design values

1. large diameter fasteners2. notching3. hanging loads4 restraint by connector unit4. restraint by connector unit

Hanger to BeamHanger to Beam

Load suspended from lower half of beamlower half of beam

T i di lTension perpendicular to grain stresses induced

Split

inducedMay cause splits

Hanger to BeamHanger to Beam

L d t d iOver top h Load supported in

upper half of beamhanger option

Extended plates puts wood in compression when loaded

compression

Local Stresses in Fastener GroupLocal Stresses in Fastener Group

Closely spaced fasteners Closely spaced fastenersbrittle failurel itlower capacity

wood failure mechanisms need to be considered inneed to be considered in design (this is in addition to yield equations)yield equations)

Local Stresses in Fastener GroupsLocal Stresses in Fastener Groups

Appendix E of NDS: fastenergroup equations/considerations

Durability and Long Term P fPerformance

Proper design MembersMembers ConnectionsP i t ll ti Proper installation Use of wet-use (durable) adhesives Protection from moisture MaintenanceMaintenance

Original U.S. Glulam StructureUSDA F P d L bUSDA Forest Products Laboratory

2008

1934

Durability and Long Term P fPerformance

Glulam Beams Stored Di ib i Y dat Distribution Yard

Glulam Beams Shipped to Job SiteGlulam Beams Shipped to Job Site

Proper handling

Proper storagep g

Interior ApplicationsD bili N T i ll A IDurability Not Typically An Issue

Golf Course BridgeGolf Course Bridge

Pedestrian Bridge - 105 ft spanPedestrian Bridge 105 ft. span Pedestrian Bridge – 120 ft. spanPedestrian Bridge 120 ft. span

Glulam Arch Highway Bridge S d d D k C l dSuspended Deck - Colorado

Glulam Arch Highway Bridge El d D k Mi hiElevated Deck - Michigan

Short Span Glulam RR GirdersShort Span Glulam RR Girders100 ft. Span Glulam

R il d Gi dRailroad Girders

Note centerspan shadow

Glulam Electric Utility StructuresGlulam Electric Utility Structures Tri-Level Highway BridgeKeystone Wye – S.D.

Originalinstallation

2009

1968 Over 40 yearsof exposureto the elements1988 to the elements

Preservative Treatment of GlulamPreservative Treatment of Glulam

U.S. Standards American Wood Preservers Standard (AWPA U1) UC1 Interior, dry Insects UC2 Interior, wet Decay and insectsUC2 Interior, wet Decay and insects UC3 Exterior, above ground Decay and insects UC4 Ground contact Decay and insects UC5 Salt water Salt water organismsUC5 Salt water Salt water organisms

American Association of State Highway and Transportation Officials (AASHTO) Above ground Above ground Ground contact, fresh water Ground contact, salt water

U.S. building codes require treatment of exposed glulam

Preservative Treatment of Glulam s

Preservative forced into wood cells under pressureunder pressure

Untreated glulam in pressure cylinder ready for treatmentready for treatment

Selecting Preservative Treatments

Preservative Treated Glulam

Selecting Preservative Treatments

Preservative Treated Glulam

Selecting Preservative TreatmentsSelecting Preservative Treatments

Applicable treatments are a function of speciesand whether treatment is before or after gluing


Retention levels mustbe met


Incising used for difficult to treat species No effect of incising No effect of incising on glulam strength

Naturally Durable SpeciesNaturally Durable Species Alaska Yellow Cedar (AYC)

S t M i CA R i CSanta Monica, CA Reservoir Cover

Van Norman Reservoir Cover inLos Angeles Using AYC Glulam

650 000 sq ft650,000 sq. ft.15 acres

Connection Serviceability IssuesConnection Serviceability Issues

Effects of MoistureEffects of Moisture Connection ServiceabilityConnection Serviceability

Effects of MoistureEffects of Moisture

SeasoningSeasoning checking Is it of structuralIs it of structural

concern?

Examples of CheckingExamples of Checking

Side checks

EndEndchecks

Bottom glue line check

Checking vs DelaminationChecking vs. Delamination

Checking is a natural phenomena associated g pwith natural drying of the glulamDelamination is a deterioration of the glue g

bond when exposed to moistureThe introduction of wet-use (durable)

adhesives in the mid 1940’s virtually eliminated delamination in the U.S.This is assured by requiring adhesives to

meet D2559 and by conducting daily quality control checks using a cyclic delaminationcontrol checks using a cyclic delaminationtest

Testing conducted to evaluate

impact of checking

Glulam Beam toC MConcrete or Masonry

Prevent contact with Note steelb i masonry

Use bearing plate

bearingplate

g punder beam Maintain minimum ofMaintain minimum of ½” air gap at end

Note gapat end

Column BaseColumn Base

ProblemNo weep holes inNo weep holes in

closed shoeMoisture entrappedMoisture entrappedDecay inevitable

Column BaseCo u ase

Bearing plate Anchor bolts in

Angle brackets Anchor bolts in bracket

bearing plate Dapped column end

Loose bearing plate

Arch Base to SupportArch Base to Support

Untreated glulamUntreated glulamarches with a closed shoeclosed shoe

No provision such as weep holes to allow

i t t d imoisture to drain


N t fl hiNote flashing ontop of glulam

Note open shoe allowing water to drain

After 25 years in service


Effects of Moisture ChangesC ion Connections

¼”Glulam¾”Sawn timber Glulam

24”15-1/4”

Green 8%

12% 8%

Green 8%

Glulam Beam End BearingGlulam Beam End Bearing

Cracks developing

Note bearing angleand slight gap at wood

Glulam Beam End BearingGlulam Beam End Bearing

Sol tion alloSolution: allow shrinkage to occur without inducingwithout inducing tension perp stresses

Slotted holes

Importance of DetailingImportance of Detailing

Ends covered

Closed shoe

Lessons Learned to Ensure Durabled L Lif Gl l St tand Long Life Glulam Structures

Keep glulam dry whenever possible Keep glulam dry whenever possible Account for moisture effectsHigh moist re = mold deca insect attackHigh moisture = mold, decay, insect attack

Protect from direct exposure to elements Use preservative treatmentsUse preservative treatmentsUse naturally durable speciesDesign connections for long term performanceg g p

Allow for movement due to moisture changesDesign to avoid moisture entrapmentAvoid direct contact with masonry and concrete

Characteristics of Glulam in FireCharacteristics of Glulam in Fire

Wood is an excellentWood is an excellent heat insulatorDevelops a char layerDevelops a char layer

after fire exposureSelf-extinguishingSelf extinguishing

after fire source removed 10-3/4 x 16-1/2

Retains significant residual strength after being exposed to fire

Glulam vs Unprotected SteelGlulam vs. Unprotected Steel Glulam After ASTM E119 Fire TestGlulam After ASTM E119 Fire Test

Char rate = 1/40” per minute

or1-1/2” per hour

Fire Rating for GlulamFire Rating for Glulam

Two accepted fire rating methodsrating methods recognized in the U.S. IBC Empirical MethodIBC Empirical MethodNDS Mechanics Based

Model

IBC MethodologyIBC MethodologyIBC MethodologyIBC Methodology

Empirical calculation protocol B d t i t ti i th Based on extensive testing in the U.S. and other countries using theASTM E119 (ISO 834) fi t tASTM E119 (ISO 834) fire test protocol Beams – 3 or 4 sides exposed Columns – 3 or 4 sides exposedp

2005 NDS Methodology2005 NDS Methodology

Chapter 16p Mechanics Based

ModelModel Supported by

empirical dataempirical data

Fire Rated GlulamFire Rated Glulam

Typical Glulam Beam LayupTypical Glulam Beam Layup

24F V4 Doug Fir (12 Lamination Example)24F-V4 Doug Fir (12 Lamination Example)

2 - L2 Dense Grade Outer Comp. Lams1 - L2 Grade Inner Comp. Lam

6 L3 G d C L

2 L2 Dense Grade Outer Comp. Lams

6 - L3 Grade Core Lams

1 - L2 Grade Inner Ten. Lam

1- 302-24 Outer Tension Lams

For 1-hour fire rated beam:

1- L1 Grade Outer Tension Lams

substitute additional tension lam for core lam

Tension Lam Provisions

Fire Protection

Tension Lam Provisions

Fire Protection

Glulam for Renovation/RehabilitationOffice Building in Portland, OR

Airport TerminalVi t i B CVictoria, B.C.

Raleigh Durham AirportRaleigh Durham AirportLight Rail Transit Center

V B CVancouver, B.C.

Chicago Bears FootballP ti F ilitPractice Facility

University of OregonF tb ll St diFootball Stadium

Twin Rink Ice ArenaA h i CAAnaheim, CA.

Chemical Storage FacilityP l d ORPortland, OR

Cathedral of Light – Oakland CACathedral of Light Oakland, CA2010 Olympic Skating Oval

Ri h d B CRichmond, B.C.

Toronto Ontario Art GalleryToronto Ontario Art Gallery Kingsway BridgeB b B CBurnaby, B.C.

Glulam Truss Bridgei Hi hi Jin Hiroshima Japan

Today’s GlulamToday’s Glulam

Additional Glulam Information

www.apawood.org

www aitc glulam orgwww.aitc-glulam.org

Questions ???Questions ???

Glued Laminated TimberGlued Laminated TimberAn Innovative and Versatile Engineered Wood ProductEngineered Wood Product

Tom Williamson, P.E.o a so ,[email protected]

Documents

Glulam Webinar compressed - WoodWorks