What is Sustainability? · APWA 2016 PWX 8/22/2016 6 Nightmare on East Street Paved in 2001, total...
Transcript of What is Sustainability? · APWA 2016 PWX 8/22/2016 6 Nightmare on East Street Paved in 2001, total...
APWA 2016 PWX 8/22/2016
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Warming up to Sustainable Paving
New England Chapter APWADavid Field P.E.
Joe FlanaganMatt LaChance
What is Sustainability?Environment
Society
Economy
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What is Sustainability?Ecologically viable and bearable
Economically equitable and viable
Socially equitable and bearable
Sustainable Pavements (Green Roads)Lower emissions and fuel consumption
Better quality construction
Recycling
Preservation maintenance
Less user delay
Smoother & quieter
Longer lasting roads costing less to maintain
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Dedham’s Sustainable Pavement Program
Dedham, MA
We are here
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Dedham, MABoston neighbor
25,000 residents
Dedham, MAApproximately 100 centerline miles
2007 PCI of 70 and falling
Underfunded maintenance budget
Entirely reliant on State funding
Roads deteriorating faster than they could be repaired
Not sustainable!
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Enter the ConsultantConducted a network wide pavement evaluation
Develop multi-year prioritised list
Select a wide range of maintenance options
Create multiple funding scenarios
Work with DPW and elected officials tosecure additional funding
The GoalEmploy multiple rehabilitation strategies
Keep the “good” roads good while improving the the poor roads
Increase the average PCI from 70 to 80 by 2017
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Nightmare on East Street
Paved in 2001, total joint failure by 2009
70% of surface course not bonded to intermediate course
20 year design life shortened to 9 years
Threatened to set back new roadway improvement program
The Lesson LearnedBetter specifications = better roads
Volumetric design with mat and joint density requirements
Appropriate lot sizes
Quality control + quality acceptance
Incentive/Disincentive
Show up for your projects!
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The FixUltrathin bonded wearing course
Placed over localized repair and crack seal
Relatively low dollar/sqyd
Returned to 20 year service life
New option for preservation maintenance
Global Warming Solutions Act, 2008In August 2008, Governor Deval Patrick signed the Climate Protection & Green Economy Act
Requires an economy-wide reduction of greenhouse gas emissions
25% reduction of the 1990 level by 2020
80% reduction of the 1990 level by 2050
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Warm Mix Asphalt, 2013MassDOT chooses WMA as the standard state specification and phases out HMA
WMA reduces fuel consumption and CO2 emissions by up to 35%
68% of the 891,000 tons of asphalt placed for MassDOT was WMA
Lower Mixing Temperatures, Lower Emissions
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What is WMA?Same materials as HMA but uses an additive to lower workable tempratures
Produced with little or no plant modifications
Placed with conventional paving and compaction equipment
HMA at lower temperatures
Warm Mix Asphalt for Municipal Paving?
Early/late season paving
Longer haul distance/time
Longer Binder life
Better compaction
Longer lasting roads!
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Advantages of Warm Mix Asphalt
Warm Mix Production Temperatures
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Longer Binder Life
Lower mixing temps result in less oxidation of the binder
Binder remains more flexible, extending the life of the pavement
Binder HardeningBinder ages the most during the mixing process
Better compaction extends the life of the pavement
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Longer Binder Life
Texas Transportation Institute Overlay Test Results
Longer Binder LifeTTI Overlay Test Results (Granite)
More flexible binders resist cracking
WMA
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Better Compaction with WMA
HMA Time Available for CompactionAt 50 deg F air temp, 2” thick, HMA has only a 19 minute window of compaction
19 min TAC
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WMA Time Available for CompactionWMA has 35 minute window of compaction
80% additional time to achieve density!
35 min TAC
Reduced Thermal Segregation
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Back to East StreetFall paving
Limited window for road closure
Unseasonably cold morning
Two paving crews on hold
WMA saves the day!
The Results
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The Results
Total Backlog: $23,652,204$10,192,000
Looking Forward
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ConclusionBy employing the use of good pavement management, preservation maintenance, and in coordination with environmentally friendlier paving techniques, better specifications, and construction oversight, it is possible to find the balance between a community's ecological, social, and economic needs, while improving the overall condition of its infrastructure.
Questions?