CIVIL ENGINEERING APPLICATIONS OF TIRE DERIVED AGGREGATE

Dana N. Humphrey, Ph.D., P.E.Professor of Civil Engineering

University of Maine

2017 Colorado WasteTire ConferenceJune 21, 2017

Tire Derived Aggregate – TDA

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

Why use TDA?• TDA is often cheapest alternative if you

need their unique properties

Why use TDA?• Can use lots of tires!!!

–75 tires per C.YD. of tire shred fill–400,000 tires for bridge

abutment, Topsham, Maine–1.2 million tires for highway

embankment, Portland, Maine–1 million tires for leachate

collection system in Delaware

Where can TDA be used?• Landslide stabilization• Lightweight embankment fill• Lightweight backfill for walls• Lightweight fill over culverts• Free draining backfill for “French Drains”• Stormwater infiltration basins• Vibration damping beneath rail lines• Backfill for residential foundations (drainage & insulation)• Insulation to limit frost penetration beneath roads• Insulation to improve performance of heat pumps• Drainage layers for landfills• Gas collection layers and trenches for landfills

Photo: Courtesy of Kennec, Inc.

Geysers road slide repair

Geysers road slide repair

Geysers road slide repair

Geysers road slide repair

North Abutment of Merrymeeting Bridge

el. 9.4 mClay

el. 5.2 m

el. 8.2 m

Type B Tire Shreds

NativeSoil

Type ATire Shreds

229 mm BituminousConcrete Pavement

AggregateSubbase

el. 11.3 m

el. 10.1 mel. 10.7 m

Station 53+35.4

CommonBorrow Granular

Borrow

AggregateSubbase

Geotextile

Piles

Station53+72.0

@ Center LineStation53+50.6

Concrete Approach Slab

4.2 m TDA

1.9 m soil cover

Initial Placement of TDA

Placement with Dump Truck

Compaction with 10-ton Roller

Goal of Presentation!

Place Soil Cover

Cost Comparison

Material Unit wt. Cost $/lb of weight credit

TDA 57 pcf $25/c.y. 0.37 Extruded

polystyrene 2 pcf $80/c.y. 0.66

Expanded shale 75 pcf $80/c.y. 1.60

Highway Edge DrainWitter Farm Road

Typical Cross Section

Place Edge Drain

TDA use in landfills

Donovan, et al., 1996

CASE HISOTRY - ChaquitaLandfill, Los Angeles County, CA

Gas Collection Trenches

• 3-ft x 3-ft trenches excavated into existing waste; perforated pipe placed in center

• TDA covered with geotextile

Chaquita Landfill

Photo: CalRecycle

Chaquita Landfill

Photo: CalRecycle

Conclusions• TDA has properties that engineers need• TDA can be cost effective• Civil engineering applications an

important use for scrap tires– Multiple highway and landfill applications

• Specifications and guidelines available• Negligible environmental effects

QUESTIONS?