Module 8 Material Resources

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Module 8Material Resources

• BCN 1582
• International Sustainable Development

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Building Materials
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Waste Quantities
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Waste Quantities
Three major waste generation activities
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Waste Quantities
Residential Demolition
National Case study average
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Waste Quantities
Commercial Demolition
Sample Composition of Commercial Demolition
Debris (19 projects in the Pacific Northwest,
R.W. Rhine, Inc., Tacoma, Washington (Franklin
Associates, 1998)).
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Demolition Waste Generation Rates
Vary depending on construction type
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Waste from Construction

• Material Tons Percent of total
• Wood 3.40 46
• Gypsum / drywall 1.88 25
• Mixed debris 1.13 15
• Cardboard 0.40 5
• Metals 0.44 6
• Masonry 0.18 2
• Total 7.43
• Waste generated 7.2lbs/SF
• Construction Waste from a 2,060 sq. ft. Single
  Family Home
• World Wastes, June, 1994.

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Embodied Energy of Materials

• Material Btu/Lb
• Gravel, stone 7-9
• Lumber 250
• Concrete 667
• Paint 4,288 - 6,514
• Glass 8,852 - 9,743
• Steel, lead 10,188 - 18,730
• Polyethylene, plastic 37,323 - 68,840
• Aluminum 82,368 - 100,235

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Characteristics of Green Materials

• Non-toxic, does no harm to occupants and
  environment
• Local
• Natural
• Low tech
• Renewable/recyclable/recycled content
• Sustainable managed and harvested
• Awareness of manufacturing impact on environment
• Durable

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Cement

• Cement - lime, silica, iron and alumina gypsum
• Lime 60-66
• Silica, 19-25
• Alumina 3-8
• Magnesia 0-5
• Ferric oxide 1-5
• 0.64 to 1.25 lb. of CO2 per lb. of cement
• Strip mining - bauxite ore, sand, aggregate

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Green Concrete - Fly-Ash

• Substitute 15-25 of cement
• Maximum 40-50 of cement
• Improves workability, reduces water requirements,
  increases the strength, reduces permeability and
  corrosion
• Fly-ash SO2 possible toxicity for interior
• Curing time 72 vs. 28 days
• Increased strength 10-15
• Less cement per unit volume and less concrete per
  load per square inch

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QUESTION?
Steel Stud
Wood

• Wood can be recycled or downcycled
• Potentially renewable resource
• Learning curve for installation complete
• Material grading and behavior established

• Steel can be recycled material
• Non-renewable
• Potential yield strength problems in fires
• Thermal transfer

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Forest Issues - General

• 55 of wood is used for fuel, remainder for
  lumber, paper, other industrial products
• Legal forest products 142 billion/yr
• Consumption per capita 12x greater in industrial
  countries compared to developing countries
• Wood production is now more efficient (23
  1945-1990)
• Wood consumption per capita in US declined by 52
  since 1990
• New products OSB, particleboard, I-joists use
  less wood and more efficiently

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Wood in Construction

• US 40 of roundwood used in construction
• 10 of worlds wood supply used in US
  construction
• Home floor area per capita in US increased 79 in
  last three decades
• During construction 10 of wood ends up as waste
  in the US
• New framing methods (Optimum Value Engineering)
  can reduce wood use and waste by 20
• Salvaged wood can be very valuable
• Certified wood Smartwood (Forestry Stewardship
  Council) protects forests

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Needed Changes

• Use certified wood or salvaged lumber
• End subsidies to forestry industry
• Recreation 2.6 million jobs 97.8 billion
• Logging 76,000 jobs 3.5 billion
• Subsidies enforce bad practices, artificially
  lower prices
• Alternative materials steel for framing, cork
  for flooring, other sources of fiber (sisel,
  jute, hemp, kenaf)

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Recycled Content - Plastic
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Recycled Plastic Lumber
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Reclaimed Lumber
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Sustainably Harvested Lumber
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Recycled and Low-Toxicity Paints
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Rapidly Renewable Fibers
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Natural Materials - Cork
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Natural Materials - Fibers
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Recycled Content - Glass
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RecycledGlass Aggregate
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Rammed Earth
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Steel Framing
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Structure as Finish
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Summer House at KBG
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Depot Kiosk
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Materials Decision Matrix

• First Cost
• Availability (materials/labor)
• Performance (Code/function)
• Aesthetics
• Life-cycle costs
• Green Building Material Criteria

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Availability

• Are green building materials readily available
  from a local source?
• Trade-offs - obtaining materials that are not
  locally available but have environmental
  attributes

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Performance

• Structural strength
• Fire resistance
• Insect resistance
• Durability and expected life-time
• Installation requirements
• Climate
• Energy
• Code acceptance

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Life-Cycle Costs

• Green building products are often perceived to be
  of lesser quality and/or of higher cost
• Savings in reduced energy costs, water use,
  maintenance and repair, etc., provide a return on
  investment competitive with other investment
  alternatives
• Also recover added value in sale of building
  (equity)
• ex. high R- value insulation - wear resistant
  materials - recycled, recyclable, salvage or
  disposal costs or benefits high-quality and
  hand-crafted materials acquire value

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CD Waste Reduction

• Waste audit identify wastes and ways to reduce
  or reuse
• Change dimensioning to reduce cut-off waste?
• Substitute with recyclable/recycled content
  material?
• Markets and service providers
• Who is available to provide materials, recover
  and reuse wastes?
• Local disposal fees
• Reuse and recycle on-site demolition material
  for site fill, non-structural aggregates, etc.
  eliminate transportation
• Off-site reuse and recycling

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Linear and Cyclical Processes
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Discussions?