Title: Timber, a truly sustainable resource, can be used to replace steel and concrete structures in multi-storey building.
1Timber, 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
2Introduction 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
3Environmental 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
4Other 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
5Study 1 Radiata Poles as the Columns in
Multi-storey Timber Building
6Study 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.
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8Study 3 Large Industrial Truss Structures Using
Pinus Radiata Poles
9Study 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
10Apartment 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
11Apartments 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
12Environmental 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.
13Building Strength
- pole members readily available
- for major earthquake zones, column pole diameters
increase by 50mm approx
14Non 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.
15Economics
- 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)
16Fire 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
17Sound 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
18Conclusions 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
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