CIVIL ENGINEERING APPLICATIONS OF TIRE DERIVED AGGREGATE

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CIVIL ENGINEERING APPLICATIONS OF TIRE DERIVED
AGGREGATE

• Dana N. Humphrey, Ph.D., P.E.Professor of Civil
  EngineeringUniversity of Maine
• Presented to
• CIWMB Waste Tire ForumMarch 9, 2006

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Tire Derived Aggregate TDA
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Why use TDA?

• TDA has properties that civil engineers need
• Lightweight (1/3 soil)
• Low earth pressure (1/2 soil)
• Good thermal insulation (8 times better)
• Good drainage (10 time better)
• Compressible
• Vibration damping

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Why use TDA?

• TDA is often cheapest alternative if you need
  their unique properties

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Why use TDA?

• Can use lots of tires!!!
• 75 tires per C.YD. of TDA fill
• 600,000 tires for Dixon Landing Interchange,
  Milpitas, CA
• 75,000 for vibration damping layer in San Jose,
  CA
• 75,000 for retaining wall backfill in Riverside,
  CA
• 2 million for highway embankment in Sabatus,
  Maine

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Civil Engineering Applications - United States
vs. California -

• Uses 21 of tires in U.S.
• Uses 5 of tires in California

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Range of civil engineering applications

• Lightweight fill for highway embankments
• Retaining wall backfill
• Vibration damping layers for rail lines
• Insulation to limit frost penetration
• Drainage layers for landfills
• Drainage layers for on-site wastewater treatment
  systems (A.K.A. septic tanks)

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Specifications

• Type A drainage, insulation vibration
  damping
• 100 passing 4-in. sieve
• Minimum of 90 passing 3-in. sieve
• Maximum of 5 passing 4.75-mm (no. 4) sieve
• Type B lightweight fill
• 100 smaller than 18-in. max. dimension
• 90 smaller than 12-in. max. dimension
• Maximum of 50 passing 3-in. sieve
• Maximum of 25 passing 1.5-in. sieve
• Maximum of 1 passing 4.75-mm (no. 4) sieve

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Dixon Landing Interchange

• PROBLEM Embankment Constructed on Bay Mud
• SOLUTION Use TDA for the core of the embankment
• CHEAPEST SOLUTION Caltrans saved 470,000

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Typical Cross Section
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Unloading TDA
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Spread with bulldozer
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Compact with 10-ton roller
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Conventional Lightweight Fill
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Unit Costs

• Cost for common borrow 7.48/yd3
• Placement costs of TDA (including
  geotextile) 3.74/yd3
• Purchase delivery costs of TDA (paid by
  CIWMB) 23.66/yd3
• In-place cost for TDA 27/yd3
• In-place cost for lightweight aggregate
  50/yd3

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Cost Savings

• Cost savings to CALTRANS with TDA provided at no
  cost by CIWMB 477,000
• Cost savings to state less purchase price of TDA
  230,000

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Why use TDA for retaining wall backfill?

• Low unit weight (50 pcf)
• Free draining (k gt 1 cm/s)
• Good thermal insulation (8 x better than soil)
• 75 tires per YD3!

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Rt. 91 Wall in Riverside, CA

• Freeway widening
• Objective show that reduced earth pressures can
  reduce overall wall construction costs
• Length 260 ft
• Tires used 75,000 PTE

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Rt. 91 wall cross section
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Compacting TDA
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Potential Future Savings for Walls

• Lower pressure on wall ? less rebar
• Potential reduction 28 tons/100 ft
• Potential cost savings 13,000/100 ft

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Vasona Light Rail Project
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Vasona Light Rail Project
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Vasona Light Rail ProjectDesign

• 12-in. ballast stone
• 12-in. subballast gravel
• 12-in. of TDA wrapped in geotextile

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Vasona Light Rail ProjectMonitoring
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Vasona Light Rail ProjectCost Savings

• Cost of conventional track 100 per track-ft
• Cost of track with TDA vibration mitigation
  121 per track-ft
• Cost of floating slab vibration mitigation
  600-1000 per track-ft
• Cost savings 479-879 per track-ft
• Total savings 1 to 2-million

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Future of TDA in California

• Two wall projects Spring/Summer, 2006
• Caltrans HQ requires TDA as first choice for
  lightweight fill
• Need to develop more projects at municipal/county
  level
• Need more processors that can efficiently make
  Type B TDA
• Significant potential for growth

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QUESTIONS?