Timber, a truly sustainable resource, can be used to replace steel and concrete structures in multi-storey building.

1
Timber, a truly sustainable resource, can be used
to replace steel and concrete structures in
multi-storey building.

• John Chapman, Senior Lecturer
• School of Architecture, University of Auckland

2
Introduction to recent timber building research -
School of Architecture, University of Auckland

• pinus radiata timber poles as the main structural
  elements in commercial / industrial building
• research is in response to the advantages of
  timber as a sustainable material
• 4 separate, but interrelated, studies

3
Environmental Reasons for radiata poles as
structural elements in building

• radiata poles are
• a renewable resource
• require little energy during manufacture
• absorb carbon from the atmosphere and reduce
  greenhouse gases

4
Other Reasons for radiata poles as building
structural elements

• Competent
• structural product
• higher failure stresses than sawn lumber
• cheap timber at NZ350/cu.m
• Images by Andrew Charleson senior lecturer
  Victoria University

5
Study 1 Radiata Poles as the Columns in
Multi-storey Timber Building
6
Study 2 Investigating Timber Floor Types for
Commercial Building

• floor structure types
• glulam
• timber trusses
• LVL (linear veneer lumber)
• office live loading of 3 Kpa
• resulting timber floors compared for cost and
  volumes of timber.

7
(No Transcript)
8
Study 3 Large Industrial Truss Structures Using
Pinus Radiata Poles
9
Study 4 Six Storey Apartment Building using
Radiata Poles for the Beam and Column Structural
Elements

• results of studies 1 to3 led to the proposal that
  timber poles were very suited for the structural
  elements in medium storey apartment building

10
Apartment Plans

• beams and posts can be arranged as simple posts
  and beams
• resistance to horizontal loads supplied by the
  frequent party walls
• floor is timber
• floor beams are pairs of radiata poles

11
Apartments Cross Section

• The research considered seven aspects of the
  prototype pole building
• dimensional stability of the timber
• environmental impact
• building strength
• non destructive testing of poles
• economics
• fire resistance
• sound insulation

12
Environmental Impact

• Pole building structure
• Energy for manufacture
• 0.5 Gj/sq.m.
• Total carbon absorbed from atmosphere
• 27.4 Kg/sq.m.
• Equivalent RC structure
• Energy for manufacture
• 2.24 Gj/sq.m.
• Total carbon emitted into atmosphere
• 52.5 Kg/sq.m.

13
Building Strength

• pole members readily available
• for major earthquake zones, column pole diameters
  increase by 50mm approx

14
Non Destructive Testing of Timber Poles

• Acousto-ultrasonic based methods relate
  propagation velocity of the longitudinal wave
  with wood density and modulus of elasticity
• Acousto-ultrasonic testing detects pole defects.

15
Economics

• pole/timber structure is 89 the cost of the
  equivalent reinforced concrete structure
• Pole building structure US124.40 / sq.m.
• Equivalent R.C. US208.70 / sq.m.
• timber buildings are significantly lighter than
  the R.C. alternatives and have reductions in
  foundation costs. (not considered in above cost
  analysis)

16
Fire Resistance

• each residential unit is an independent fire cell
• pole structure party walls are plasterboard
  lined
• 80mm expected loss of pole diameter in 1 hour
  fire
• Poles will continue to support building after 1
  hour fire

17
Sound Insulation

• 50mm thick concrete floor toppings to protect
  from vertical noise transference
• Horizontal insulation at party walls assisted by
  fibreglass blanket between two separated timber
  frames
• Sound transference the main obstacle to timber
  building. Research occurring at the University of
  Auckland Acoustics Research Centre and elsewhere
  in world

18
Conclusions to Radiata Poles as the Columns in
Multi-storey Timber Building

• no impediments to radiata poles as main
  structural members in multi-storey of up to at
  least 6 storeys
• 6 storey apartment building most complete project
• considered more deeply the issues and perceived
  problems
• Further research into this low energy,
  sustainable, and atmosphere assisting building
  product is continuing

19
(No Transcript)