Clt mtb seminar_presentation_five

756 views

Published on

Published in: Design, Business, Technology
0 Comments
1 Like
Statistics
Notes
  • Be the first to comment

No Downloads
Views
Total views
756
On SlideShare
0
From Embeds
0
Number of Embeds
50
Actions
Shares
0
Downloads
27
Comments
0
Likes
1
Embeds 0
No embeds

No notes for slide

Clt mtb seminar_presentation_five

  1. 1. LVL Floor Panel SystemsMassive Timber Seminar18th June – Sydney19th June – MelbourneAuthored and presented by Andy Van Houtte
  2. 2. LVL Flooring Panel CharacteristicsDesign Solutions• Light weight structures• Flexible designs• Multiple geometries• Acoustic solutions• Fire rating solutions• Composite actionConstruction Advantages• Speed of installation (less overall workers on site)• Smaller cranes or larger reach (multiple lifts)• Smaller supporting structures (1/5th the mass of concrete)• Less truck movements• Smaller/less expensive foundations• Cleaner work environment – dry site• Quieter work site• Easier to install services• Instant working platform
  3. 3. Panel options1. T-beam• bottom flange2. Cassette• Bottom flange fire rated3. Concrete top• Partial composite action4. Hanging ceiling• fire performance/acousticalTop Skin SizesXband LVL 17, 21, 25, 36, 45mmLVL JoistsThicknesses 35, 45, 63, 90mmWidths 150, 200, 240, 300, 360, 400, 460, 600mmLength up to 18m
  4. 4. T-Panels1. Simple to fabricate2. Cost effective – glue and nail/screw3. Fast to install4. Full composite action with floor sheathingcan be achieved with long length xband LVL5. Residential and commercial applications
  5. 5. Cassette Floors1. More expensive than T-beam to fabricate2. Not a total solution3. Dynamics can govern due to light weight1. Good span to weight ratio2. Bottom flange can act as sacrificial firebarrier3. Between joists can support services andinsulation.4. Can be used for hit and miss flooringeffectively.
  6. 6. Concrete toppingAdvantages• Thermal mass• Rigid diaphragm action• Dynamic damping• Acoustical absorption• Partial composite action possible• Potential for pre fabricationDisadvantages• J2 factor 3-4 (composite action only)• lots of mechanical fasteners/notches for composite action• Concrete shrinkage• Wet trade on site2 2( )ef c c t t c c c c t t t tEI E I E I E A a E Aa    
  7. 7. Cost versus SpanSpan (m)$/m21001201401601802002202404 5 6 7 8 9 10 11Cassette FRR60T BeamT Beam FRR60Design loadings:3kPa live load2kPa superimposed dead loadNo concrete composite actionconsideredConcrete cost not included
  8. 8. Panel DesignStrength1. Bending strength limited by concrete capacity2. Bending strength limited by timber capacity3. Shear strength4. Shear Connector CapacityDeflectionDynamicsTraditionally fundamental frequency greater than 8Hz was employed to provide a guideline for the measure of a suitable floor response.This was simplified in AS1684 – residential framing (based on research by Mackenzie and Juniper, 1997) to a maximum deflection of 2mmunder a 1kN point load (in conjunction with the load distribution factor) for timber joists.More recently a more relevant method of measuring dynamic acceptability is by the floor acceleration (RMS), with different responsecriteria given the intended purpose of the floor. A good resource is the UK Concrete Society CCIP-016 report – Design Guide for footfallinduced vibration of structures or alternatively using the rigorous analysis (SCI P-354)
  9. 9. Spreadsheet design – makes it easyStress Skin PanelsJoist spacing 600 mmMoE of system 11 GPaTotal thickness 720Laminate count 12Geometrical centroid of section 420.62Structural centroid of section (Stiffness) 445.472nd moment of Inertia (Geometrical) 0.000192nd moment of Inertia (Structural) 0.00019Note: Cross ply contributes 0.3ETop Flange Web Bottom FlangeLaminate Depth (mm) Width (mm) Contribution for IContribution forZ E (GPa) Fb (Mpa) Depth (mm)Width (mm) Contribution for I Contribution for Z E (GPa) Fb (Mpa) Depth (mm) Width (mm)1 3.5 400 1 1 9 352 3.5 400 1 1 9 353 3.5 400 0.3 0 9 354 3.5 400 1 1 9 355 3.5 400 1 1 9 356 3.5 400 1 1 9 357 3.5 400 1 1 9 358 3.5 400 0.3 0 9 359 3.5 400 1 1 9 3510 3.5 400 1 1 9 3511 610 45 1 1 11 3813 75 40014151617iibhE ÷÷øöççèæ123zE A zE Ai i ii i__ååEE I A E z zI A z zi i i i ii i i - -ååå å( )( )_ __ __22I I A z zi i i  -å å ( )_ __22__)( Siii zzEA -LVL Floor joists (mm) kg/m2Supporting floor loads only, also not including deck joists Bearer width 75 Floor Dead Load 40E value 10700000000 fs 6000000 loadsfb 42000000 fp 12000000 DL DL LL LL LL LL LL LL LLJoist spacing G1 G2 Q1 Q2 Q3 Q4 Q5 Q6 Q7Member B D I Z Reference Estimated length (mm) (kN/m) (kN) (kN/m) (kN/m) (kN/m) (kN/m) (kN) (kN) (kN)400x45 45 400 240000000 1200000 16 4.5 400 0.257 0.000 0.200 1.600 0.300 1.200 2.22 6.00 0.65400x45 45 400 240000000 1200000 16 4.5 450 0.277 0.000 0.225 1.800 0.338 1.350 2.20 6.75 0.64400x45 45 400 240000000 1200000 16 4.5 600 0.337 0.000 0.300 2.400 0.450 1.800 2.41 9.00 0.75Bending Deflection Shear Bearing1 2 3 hb hc g42 g41300 0.20 0.05 0.24 0.17 0.15 0.52 28.18 120.9 0.82 0.65450 0.22 0.06 0.27 0.17 0.17 0.59 28.18 131.4 0.82 0.64600 0.29 0.07 0.36 0.20 0.22 0.78 28.18 55.4 0.89 0.75Bending Deflection Shear Bearing All300 OK OK OK OK TRUE450 OK OK OK OK TRUE600 OK OK OK OK TRUE
  10. 10. Acoustics and Fire PerformanceFire Resistance Ratings requires typically 60, 90 or120mins in Australia,Options:1. Can be achieved with a fire rated plasterboard ceiling2. Can be achieved with LVL char rating of 0.7mm/minAcoustics – impact and airborne transmission1. Best performance achieved with an acousticalbreak – like a hanging ceiling2. Floor toppings3. Sound insulation internally between joists
  11. 11. Reference Material1. Potius Panels - www.potius.co.nz2. STIC EXPAN Material (UTS) – Keith Crews, Rijun Shrestha, Christophe Gerber3. A dynamic approach for timber floor design - Chui and Smith4. Composite Concrete slab and LVL floor systems – Fragiacomo and Deam5. Eurocode 56. Timber Designers Manual - Ozelton and Baird7. Springiness and Human induced floor vibrations – Ohlsson8. Timber Design Guide – Buchanan9. Mackenzie and Juniper – timber framed housing – methodology and performancecriteria
  12. 12. Thank you

×