PowerPoint Presentation NORTH AMERICAN SOCIETY for TRENCHLESS TECHNOLOGY NODIG 2004

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Effective and Environmentally Friendly Utility
Cut Repairs
UTILITY INDUSTRY WORKSHOP 2009 AASHTO
Right-of-Way Utilities Subcommittee
Conference Oklahoma City, OK
Marshall Pollock Utilicor Technologies
Inc. Toronto, Canada
April 20th, 2009
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U.S. Underground Infrastructure 20 million
miles of pipe, cable and wire - much of it buried
in the Right-of-Way

• Electrical cables
• High and low voltage
• Signal cables
• Cathodic protection cabinets and cables
• Conduit systems, cable pits and chambers
• Gas lines
• Distribution lines (high, medium and low
  pressure, cast iron, steel, Polyethylene)
• Mains and Services (fittings, valves, service
  joints, casings, tracer wire, cathodic
  protection)
• Petroleum Lines
• Communication cables
• Phone lines -- copper and fibre optic
• Conduit systems
• Coaxial and data cables
• Sewer/water mains and services
• Pits
• Tunnels
• Connections
• Valves
• Steam Lines

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Conventional Access to Buried Utilities

• Repair Replacement Existing infrastructure has
  become very congested and is wearing out and
  needs to be repaired or replaced.
• New Installation We continue to add and change
  utilities because of expansion, modernization and
  changing missions.
• Poor Pavement Repair Once the work has been
  completed, if the repair is not properly done,
  the repaired pavement will settle or crack and
  allow groundwater to penetrate.
• Failure Groundwater is the most common cause of
  pavement failure and potholes.

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Conventional Excavation Methods

• Damage Careless ROW excavation can result in
  destruction of underground facilities, damage or
  injury.

• Delay Road work and utility cuts cause 400
  million hours of traffic delay and disruption,
  cost drivers 6 Billion in wasted time and
  collectively waste 2.3 Billion gallons of fuel
  annually.

• Reduced Life Expectancy Conventional utility
  cuts through pavement can significantly reduce
  the life expectancy of roads.

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Conventional Utility Cut Repairs
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Conventional Utility Cut Repairs
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Resulting in Potholes
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Excavation Innovation
Prehistoric Sharp Sticks
1800-1900 Hand Digging
1900-1950 Trenching Machines
1950-Present Vacuum Excavating
1990-Present Coring and Reinstatement
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Coring and Reinstatement
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Keyhole Coring and Reinstatement

• A better, smarter and environmentally sensitive
  way of locating utilities and making and
  repairing utility cuts through pavement to
• Reduce delays and disruption of traffic and
  public inconvenience during roadwork
• Minimize damage to roads
• Reduce impact of public works construction on the
  environment
• Facilitate repairs to underground utilities
• Improve worker safety and productivity through
  better excavation methods
• Avoid damage to underground utilities during
  excavation or HDD (Potholing)
• Locate and map underground utilities (S.U.E.)
• Save utilities and their contractors time and
  money

• A Core Strategy for Utility Cut Repairs

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Coring and Reinstatement History

• 1988 Coring Consumers Gas (Toronto) uses Rotary
  Coring equipment for cathodic protection, leak
  repair and main separation
• 1992 Core Reinstatement program begun with
  Golder Associates -- tested 25 grouts
• 1993 Utilibond developed, tested approved by
  Ontario Ministry of Transportation (Feb. 1994)
• 1992-95 Field Test 892 keyhole jobs
  successfully performed
• 1996 Pilot Project Metro Toronto authorizes
  coring reinstatement pilot project
• 2002-4 Approval City of Toronto approves coring
  reinstatement process
• 2007 Standard City of Toronto prescribes coring
  reinstatement Standard.

THE FIRST DEMONSTRATION July 22, 1998 Consumers
Gas demonstrates to GRI its field operational
crew truck with a special circular, asphalt
cutter for keyhole maintenance jobs.
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Proof of Process

• Golder Associates 10 year Engineering study
  (1992-2002)
• Based on trials carried out at our testing
  laboratory and our in-field performance
  observations, we are satisfied that the
  equipment, procedures and materials developed and
  used by Enbridge Gas Distribution over the last
  10 years will ensure satisfactory long term
  performance of the pavement reinstatement.
• The pavement coupon has been bonded into the slab
  in such a manner that the loads of traffic are
  effectively transmitted to the remaining intact
  slab.

TEST degree of coupling between undisturbed
road structure and newly restored cut.
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Golder Report
Fast Setting, Rapid Strength Gain Convenient,
Consistent, Replicable
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Restoration of Utility Cut Study

• Joint project of North American cities, utility
  companies and U.S. state departments of
  transportation (2000-2005).
• Objective to develop a guide for best
  restoration practice based on sound engineering
  principles.
• Toronto Field Experiment Observations

• ROTARY CUT KEYHOLE
• No defects in keyhole cut.
• Keyhole section established Oct. 2001 continued
  to perform well throughout life of project.
• Surface of restored keyhole remained level with
  the road profile.
• The bonding material surrounding the AC/PCC core
  remained intact (no cracking or separation.
• Waterproof bond.

• CONVENTIONAL TRENCH
• Noticeable failures in conventional cut.
• Conventionally repaired joint between road and
  the cut opened.
• Visible settlement in trench along wheel path.
• Material used to seal joint lost under action of
  traffic.
• Sand cover at base of trench exposed to higher
  than normal levels of moisture (compared with
  keyhole).

Keyhole construction is an effective restoration
technique that should be encouraged whenever
feasible to minimize need for opening large
trenches in the future.
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Conventional Repair Failures
The material used to seal the joint was lost
under the action of traffic as a result of shear
flow or pullout of the sealant, allowing
groundwater penetration.
South edge of Trench
North edge of Trench
Source Joint Utility Cut Study Toronto Field
Experiment, US Army Corps of Engineers and NRCC.
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Keyhole Findings Conclusions

• No Distress The keyhole restored October 2001
  showed no distress during the inspections
  performed during the May 2002 and April 2003
  visits. The grout remained intact and the surface
  is level with the road.

• Level -- No separation The surface of the
  restored keyhole remained at level with the road
  profile. The grout Utilibond surrounding the
  AC/PCC plug remained intact (no cracking or
  separation).

• Lower Stress Levels The keyhole opening is quite
  small (18 in., 457 mm, in diameter) compared with
  the area of a tire print of heavy trucks in
  contact with the road surface. As a result, low
  stresses are transmitted to the underlying
  sections of the restored keyhole.

• No Pressure Cracks Based on basic rules of
  mechanics, a circular cut shape in the AC is
  ideal for preventing propagation of cracks into
  the surrounding road area.

The keyhole construction and restoration
technique should be encouraged whenever feasible
to minimize the need for opening large trenches
in the future.
Source Joint Utility Cut Study Toronto Field
Experiment, US Army Corps of Engineers and NRCC.
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Deteriorating Road Conditions

• 23 major metropolitan roads interstates,
  freeways and other critical local routes have
  pavements in poor condition, resulting in rough
  rides.
• 413 annually in additional vehicle operating
  costs due to accelerated vehicle deterioration,
  additional maintenance needs and increased fuel
  consumption.

2008 TRIP Report
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Problems with Utility Cuts
Conventional Methods
Coring Reinstatement

• Excavation Jack hammers and backhoes caused
  measurable damage to the unexcavated structure.

• Excavation Surgical precision of coring saw
  causes no damage to pavement or to the
  unexcavated structure.

• Backfilling Poor or irregular backfill
  compaction. Did not follow proper procedures
  requiring 8-10 lifts and 95 Proctor. Poor
  inspection.

• Backfilling New backfill monitoring technology
  (Soil Compaction Supervisor) accurately monitors
  compacted soil density in real time can be
  audited by supervisors and municipality for
  accuracy. No on-site inspection needed.

• Failure to obtain waterproof joint Tack coats
  and sealants lack adhesive and cohesive strength
  causing separation from the vertical edges of the
  asphalt cut. T-section cut backs exacerbate the
  problem by trebling the length of the perimeter
  cut.

• Waterproof Bond Utilibond proven to create
  high-strength waterproof mechanical joint capable
  of supporting more than 50,000 lbs in 30 minutes.

• Geometry Circular cut has no corners or straight
  edges.

• Geometry Rectangular shape concentrates pressure
  in corners causing pressure cracks. Cut line
  parallel to traffic results in differential wheel
  pressures which can open cut.

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Reduced Zone of Influence
Zone of Influence
The precise coring process when combined with
vacuum excavation reduces loading adjacent to the
excavation and reduces or eliminates any zone of
influence.
Zone of influence is the area around the
excavation that is susceptible to slippage or
collapse resulting from external surface load,
from vehicles, plant, or excavated material at
or near the excavation.
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Keyhole coring and reinstatement is a better way

• Reduced Traffic Disruption Faster, one-step
  permanent pavement repair means reduced traffic
  congestion with fewer and shorter road closings
  and no repeat visits.
• Reduced Pavement Damage Less intrusive, more
  precise pavement coring and reinstatement process
  means less structural damage to road system,
  longer pavement life and reduced maintenance.
  Saves millions of tax dollars.
• Reduced Footprint Neat, almost invisible 18 inch
  diameter circular cut (less than 1/4 the size of
  conventional road cut), means less scarring of
  the landscape and better pavement performance (no
  corner cracks).
• Environmentally Friendly No road-cut spoil to be
  disposed of and no temporary patching compounds
  with volatile organic compounds (VOCs) to escape
  into the atmosphere.
• Cleaner, Safer, Less Intrusive Worksite No
  jack-hammers or large excavation equipment means
  less mess during and after excavation and reduced
  disruption for neighbors.
• Huge Cost Savings for Utility No repaving
  required, saves time and resources -- can reduce
  costs by more than 50 - 60.

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What is Keyhole Technology?

• Method of accessing or viewing underground
  utilities or plant through small holes or
  keyholes
• vacuum excavated through soft surfaces or through
  holes cut or cored through pavement.

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Why Keyhole?
Smaller is better and less intrusive.

• Keyhole Operation
• Smaller Opening (keyhole)
• Faster Restoration
• Less Damage to Road System
• Smaller Repair Footprint
• Lower Cost

Laparoscopic Surgery

• Smaller Incision
• Short Recovery Period
• Faster Healing
• Smaller Scar
• Lower Cost

• and safer -- no men in the hole.

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Keyhole Coring and Reinstatement
Size Matters !

• Smaller, Less Intrusive
• NO jackhammers, backhoes
• NO spoil or waste
• NO zone of influence -- NO Cutbacks
• Size and Shape
• Rectangular cuts concentrate stress
• Circular geometry with NO corner cracks
• Proven Strength -- NO Failures
• Reinstated core will support 50,000 lbs
• Greater Satisfaction -- Reduced Delay
• Reduced pavement deterioration -- NO potholes
• Reduced traffic delay -- no additional road
  closing for repaving -- In and Out the same day.
• Aesthetically pleasing -- almost invisible repair
  
• Reduces Pavement Restoration Cost by 87

No Corner Cracks
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Keyhole Repairs
Keyhole repairs are made from the surface using
long-handled tools.

• Typical Gas Applications
• Cast iron joint repair
• Sacrificial anode installation
• Low pressure service cut off
• New service installation
• High pressure PE pipe repair
• Daylighting for directional drilling
• Pipeline integrity inspection

• Typical Water Applications
• Cathodic Protection
• Service connection after pipe-splitting
• Daylighting for directional drilling

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Utilities Using Keyhole Technology

• Alagasco
• Atlanta Gas Light
• Atmos Energy
• Baltimore Gas Electric
• Centerpoint Energy (Houston)
• Centerpoint Energy (Minnegasco)
• Colorado Springs Utilities
• Connecticut Natural Gas
• Consolidated Edison
• Enbridge Gas Distribution
• Energy East Corporation
• Equitable Gas
• Keyspan Energy Delivery
• Las Vegas Valley Water District
• Michcon (DTE)
• National Grid
• Nicor Gas
• Northwest Natural
• Pacific Gas Electric

• Peoples Gas
• Philadelphia Gas Works
• PSNC Energy
• Questar Gas
• Sempra Energy
• Southwest Gas
• UGI Utilities
• Washington Gas Light
• WE Energies
• Xcel Energies

• Under Review
• Consumers Energy
• CINergy
• Dominion East Ohio Gas
• Knoxville Utilities
• National Fuel Gas
• NSTAR
• NYSEG
• Oklahoma Natural Gas
• South Jersey Gas

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Keyhole Conflict Identification

• Keyhole Coring and Vacuuming process allows you
  to identify and expose exact location of
  potential conflicts in advance of directional
  drilling
• After drilling, conflict hole is back-filled and
  pavement core reinstated -- as a permanent repair.

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Expose Multiple HDD Conflicts

• HDD to connect services on east side with new 4
  PPE main on west side
• Needed to identify
• 48 trunk water main,
• 8 water main, and
• 6 gas main under road
• concrete telephone duct and
• high voltage electric conduit under sidewalk
• 5 inspection holes cored and reinstated along
  drill shot.

• At least 2 lanes of traffic maintained at all
  times.

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Keyhole Technology is a Process
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Coring Process
Series 500
Minicor

• Coring trucks or skid-steer mounted Minicor unit
  sets up at the repair site and cores an 18 hole
  through the roadway at previously located
  maintenance sites or potential HDD conflict sites
  (gas, water, sewer, fiber optic cable etc.).

MD100
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Rotary Coring Process (continued)

• 18 - 24 diameter hole up to 22 deep
• neat and accurate
• Time 10-15 minutes depending on depth and
  composition
• Center pilot hole is cut simultaneously

Source National Grid
View Inside coring drum showing center pilot bit
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Rotary Coring Process (continued)
Cuts cores of different depths and materials
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and get into tight spaces
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Sometimes two holes are better than one

• When one 18 or 24 inch hole isnt wide enough --
  then two can be better
• and achieve the same economies in restoration
  costs and speed in reopening the road to traffic.

Effective Opening Size 30 inches x 12 inches
(18 inch drum) 42 inches x 18 inches (24 inch
drum)
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Rotary Coring Process (continued)

• Once the core has been cut through
• a core puller is used to remove the core
• The core is set aside (to be reinstated later).

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Vacuum Excavation

• the hole can then be vacuum excavated and the
  exact location of the potential conflict
  identified or the plant to be repaired exposed.

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Backfilling

• The hole is then back-filled and compacted to the
  level of the base of the pavement so that the
  core or coupon of pavement can be reinstated.

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Reinstatement of the Core

• A layer of pea gravel is used to level out the
  base and the Utilibond is mixed with water and
  poured into the hole

the core is reinserted into the hole and fitted
to the level of the surface.
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Bond Strength

• Tests of 3 commercially available bonding
  compounds were conducted in July 2003 at the
  Department of Civil Engineering, University of
  Illinois at Urbana-Champaign.
• The Utilibond bonded core gained sufficient
  strength within 30 minutes to support the
  combined weight of five transit buses -- over
  52,000 lbs.
• Safety Factor 5 times the AASHTO H-25 standard.

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Fast-Strength Gain
Time is money and Convenience !

• Utilibonds rapid hydration and ultra-fast
  strength-gain allows roadways to be re-opened in
  30 minutes.
• Resulting in crew time savings of more than 70
  per hole over other bonding products with slower
  strength-gain.

• Greater Public Convenience road open to traffic
  again at least 1 hour sooner than conventional
  methods.

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The Completed Repair

• Utilibond sets-up in 10-15 minutes
• Bond gains sufficient strength in 30 minutes to
  support the single axel equivalent load equal to
  five transit buses
• 5 times the AASHTO standard or over 50,000
  pounds.
• Coring reinstatement cost 375

• The road can be safely reopened in 30 minutes!

with no subsequent repaving required
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Excavation Alternatives
Jack hammer and Vacuum
Jack hammer and Hand Digging
Coring and Vacuum
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Excavation and Repair Results
Conventional Rectangular Cut
Temporary Patch
Permanent Keyhole Core Reinstatement
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Excavation and Repair Results
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Advantages of Coring Reinstatement

• Operationally Superior
• Aesthetically Pleasing
• Functionally More Effective
• Field Proven and
• Environmentally Friendly.

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Operationally Superior

• Reduced pavement restoration
• Improved Logistics Single crew, one-stop,
  same-day coring and pavement reinstatement means
  simplified scheduling, no temporary patching or
  repaving and no repeat visits.
• Shorter and fewer road closings
• Fewer complaints about traffic disruption,
  weakened or failed roads.
• Faster, safer and physically less demanding on
  work force -- no jack hammers and reduced
  potential for workplace injury
• Less damage to the road system -- NO potholes

A coring, vacuuming process.
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Aesthetically Pleasing

• Creates favorable impression with the public
• Rotary cored and reinstated access hole almost
  invisible in the foreground. (Permanent)
• Conventionally repaired sidewalk cut in
  background. (Temporary)
• No unsightly utility cut reminders or potholes.
• No stress cracks or other failures.
• No slip, trip and fall litigation.

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Functionally More Effective

• Works better -- less damage to pavement
• Reinstated core exactly matches the original
  pavement profile.
• The pavement system is restored to its original
  design specifications -- no deterioration in
  performance.
• No stress cracks, ground water penetration or
  premature failure.
• Road re-opened to traffic much sooner -- less
  inconvenience to public.
• KEY ISSUES for the DOT and municipalities.

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Field-Proven Process

• Core Reinstated 1995

Same Core 2003
Since the initial reinstatement, more than
145,000 transit buses and more than 13 million
commercial and other vehicles have passed
directly over the keyhole with no apparent
weakening or other degradation of the reinstated
core or the adjacent road system or paved
surface.

Golder Associates April 21, 2003
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Environmentally Friendly

• Reuses the same material, in the same form, to
  repair pavement
• - no additional processing needed
• - no additional energy consumed
• Savings 2 tons of asphalt concrete
• No pavement spoil to be trucked away to dump site
• Savings 27 cubic feet of spoil
• No new pavement laid, no milling overlay, no
  slurry etc.
• - no volatile organic compounds (VOCs) to
  evaporate
• - fewer GHG emissions
• - no additional energy or oil consumed in
  producing/heating HMA
• Savings 2 tons of asphalt concrete fuel
  better air quality
• Shorter and Fewer Road Closings
• - road can be safely reopened to traffic in
  30 minutes
• - permanent repair -- no additional site
  visits
• - reduced inspection traffic control
  requirements
• Savings 3-5 hours reduced work zone delay

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Environmental Benefits (contd)

• Minimal Dust and Vibration
• - no dust -- water slurry easily vacuumed
• - no vibration and pounding or damage to zone
  of influence
• Savings better air quality reduced impact
  on neighbors
• Reduced Noise
• - coring saw 85-90 dB vs jackhammer 115-125 dB
• - no large equipment, trucking or paver noise
• Savings work zone 8 times quieter
• Restored Road System with Waterproof Bond
• - no cracks, escaped sealant, or water
  infiltration
• - performs as load transfer system
• Savings a better road system
• Reduced Cost
• - 75 vs 500-600 conventional pavement
  repair with T-section
• - 75 vs 1,200 for mill and overlay
• Savings 425 to 1,125 per utility cut

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Reduced Carbon Footprint
Coring
Conventional
1
1
Saw Cut
Excavate Pavement
Dump Spoil
Excavation
Vacuum
Core
Vacuum
Temporary Asphalt Patch
Compact Patch
Same Day
Months Later
2
Restoration
Excavate Patch
Dump Spoil
Reinstate
Finished Repair
Concrete Base
Asphalt Surface
Compact Surface
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FHWA Recycled Material PolicyReduce Re-use
Recycle
The same materials used to build the original
highway system can be re-used to repair,
reconstruct, and maintain them. Where
appropriate, recycling of aggregates and other
highway construction materials makes sound
economic, environmental, and engineering sense.
The economic benefits from the re-use of
nonrenewable highway materials can provide a
great boost to the highway industry. Recycling
highway construction materials can be a
cost-saving measure, freeing funds for additional
highway construction, rehabilitation,
preservation or maintenance. Recycling presents
environmental opportunities and challenges,
which, when appropriately addressed, can maximize
the benefits of re-use. The use of most recycled
materials poses no threat or danger to the air,
soil, or water. Furthermore, careful design,
engineering and application of recycled materials
can reduce or eliminate the need to search for
and extract new, virgin materials from the
land. The engineering feasibility of using
recycled materials has been demonstrated in
research, field studies, experimental projects
and long-term performance testing and analysis.
Significant advances in technology over the past
decade have increased the types of recycled
materials in use and the range of their
applications. When appropriately used, recycled
materials can effectively and safely reduce cost,
save time, offer equal or, in some cases,
significant improvement to performance qualities,
and provide long-term environmental benefits.
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3.6 million Utility Cut Permits(issued by
municipalities every year )
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20-25 Utility Cut Permits for Small Holes
Estimated that 700,000 - 900,000 utility cut
permits in US issued each year for work that can
be performed through a 2 ft x 2 ft or 2 ft x 3 ft
or smaller opening -- perfect for keyhole work
Conventional small utility cuts
18 in diameter keyhole cut
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Potential Nationwide Impact of Coring
If 800,000 utility cuts were performed with
keyhole coring and reinstatement, ANNUAL savings
would be
Reduction in asphalt used 2 million tons --
equal to 20,000 mi 4-lane highway
Reduction in spoil disposal 27 million cu.
ft. -- enough to fill 200,000 dump trucks
Reduction in work zone delay 2.8 million hours
1.9 million gal fuel 520 million cost
Restoration Cost Savings 340 to 900 million
Reduction in GHG, VOCs and other emissions,
energy consumption, noise, inconvenience,
complaints
. Priceless !
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27 million cubic feet Road Spoil
Equivalent of 10 football fields stacked 50 feet
high
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Summary of Advantages

• FOR THE UTILITY/CONTRACTOR
• Saves Money Dramatically reduced paving budgets.
• Positive Community Relations Faster, less
  intrusive process. Fewer complaints from
  municipalities about traffic disruption,
  unsightly road cuts, sunken patches or weakened
  or failed roads.
• Improved Logistics Single crew, one-stop,
  same-day coring and pavement reinstatement means
  simplified scheduling, no temporary patching or
  repaving and no repeat visits.
• Field-Proven Process Zero reported failures in
  more than 15 years and over 60,000 successful
  corings in tough urban climates.
• FOR THE CREW
• Easy to Operate No extensive training required.
• Easy on the Back Physically less demanding, no
  jack-hammers, shovels and backhoes. Reduces
  potential for workplace injury.
• Easy to Use Utilibond packaged in easy-open,
  pre-measured polyethylene pails. Just add water,
  mix and pour. No awkward measuring from fragile
  paper bags.

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Summary of Advantages (continued)

• FOR THE COMMUNITY
• Reduced Traffic Disruption faster, one-step
  permanent pavement repair means reduced traffic
  congestion with fewer and shorter road closings
  and no repeat visits.
• Saves Tax Dollars Less intrusive, more precise
  pavement coring and reinstatement process means
  less structural damage to road system, longer
  pavement life and reduced maintenance. Saves
  millions of tax dollars.
• Reduced Footprint neat, almost invisible 18 inch
  diameter circular core (less than 1/4 the size of
  conventional road cut), means less scarring of
  the landscape and better pavement performance (no
  corner cracks).
• Environmentally Friendly No road-cut spoil to be
  disposed of and no temporary patching compounds
  with volatile organic compounds (VOCs) to escape
  into the atmosphere, and no wasteful T-section
  cutbacks needed.
• Cleaner, Safer, Less Intrusive Worksite No
  jack-hammers or large excavation equipment means
  less noise and mess during and after excavation
  and reduced disruption for neighbors.

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Questions and Discussion
Marshall Pollock Utilicor Technologies Inc. Toll
Free 888-572-6666 Emailinfo_at_utiilicor.ca Website
www.utilicor.ca