Transcript
Sustainable PavementsGreen Thinking for Black Roads
Presented to:Matthew J. LaChance
Date, 2013
• Capable of being sustained
• or, relating to, or being a method of harvesting or using a resource so that the resource is not depleted or permanently damaged
• leaving the world in better condition than you found it
What is Sustainability?
Components of Sustainability
Dwindling natural resources
Reducing and reusing waste material
Reducing emissions and “greenhouse gases”
Reducing fossil fuel consumption(Current supply = 1,258b barrels/31b barrels per year = 40 years remaining*)
* HMAT 4/2011 – Stephen Muench, University of Washington
Ecological Considerations
User delay
Ride Quality
Noise
Public relations
Social Considerations
Longer lasting pavements cost less
Lower resource usage = lower costs
Lower fuel usage = lower costs
Smooth pavements reduce operating costs
Economic Considerations
Recycling
Warm Mix Asphalt
Porous Pavement
Longer Lasting Pavements
Pavement Preservation
Smooth Pavements
Sustainable Paving Practices
Recycling – 1970’s
Warm Mix Asphalt – 2000 (Europe)
Porous Pavement – 1980’s
Longer Lasting Pavements
Pavement Preservation
Smooth Pavements
Not New!
Are Sustainable Practices New?
Recycled HMA (RAP)(hot & cold in place & central plant)
Asphalt Shingles
Crumb rubber
Full depth reclamation
Recycling
Uses same materials as HMA with an additive to lower workable temperatures
Increased RAP content is possible with lower mix temperatures
Warm Mix Asphalt
Three Methods:• Wax Additive
• Chemical Additive
• Steam (requires plant modification)
Warm Mix Asphalt
Warm Mix Asphalt
Hot Mix (300 F) WMA (250 F)
Improved working conditions
Lower fumes and emissions
Lower fuel consumption
Lower plant wear
Decreased binder aging
Increased plant production
Potential Benefits:
Warm Mix Asphalt
Extended Paving Season or Paving Day
Cool weather paving
Compaction aid for stiff mixes
Longer storage
Longer haul distances
Allows drainage of water directly through pavement structure
Reduces the need for detention ponds
Requires specially designed pavement and substructure
Improves water quality
Reduces stormwater runoff rates
Porous Pavement
Properly Designed
Enforceable specifications
Construction oversight for specification compliance
Longer Lasting Pavements
Paving Mixture Design
Pavement Structure Design
Perpetual Pavement
Proper Design
Key Factors:• Material sampling at intervals appropriate for project size
• In-place mat density
• Joint density requirements
• Quality factors at the production facility
• Incentive/disincentive
• Smoothness requirements
Better Specifications
Sampling and testing at production facility during production/placement
Job site construction oversight • In-place density testing (QC)
• Core sampling for payment factors (QA)
• Smoothness testing of final surface via rolling straight edge or profilometer
Construction Oversight
Timely routine and preventive maintenance reduces the frequency of resurfacing
Energy consumption, aggregate consumption, and green house gas emissions are all reduced by the use of preventive maintenance treatments
Pavement Preservation
ISSA 45th Annual Convention - February 2007
Pavement Preservation
ISSA 45th Annual Convention - February 2007
Pavement Preservation
FHWA study* indicates a 4.5% fuel savings for a 10% improvement in IRI (50% improvement in IRI common for resurfacing projects = 22.5% fuel savings)
Typical municipal street – one mile long, ADT=2,000,assume MPG=15 on poor condition road. Resurfacing will save 10,950 gallons/year!
** TRIP – September 22, 2010
* WesTrack Facility, Nevada
Smooth Pavements
“Twenty-four percent of the nation’s major metropolitan roads – interstates, freeways and other critical local routes – have pavements in poor condition, resulting in rough rides and costing the average urban motorist $413 annually in additional vehicle operating costs due to accelerated vehicle deterioration, additional maintenance needs and increased fuel consumption”
** TRIP – September 22, 2010
* TRIP 2008
* WesTrack Facility, Nevada
Smooth Pavements
53 percent improvement in road smoothness resulted in a 2.46 % improvement in miles per gallon for large trucks.
With approximately 9,000 large trucks per day on I-70, over the course of a year the annual fuel savings would be 3,120,750 gallon of diesel. At the Nov. 16, 2006 average price per gallon of $2.56, the annual cost savings would be $7,989,120.
** TRIP – September 22, 2010
* WesTrack Facility, Nevada
MoDOT Pavement Smoothness and Fuel Efficiency 2006
Smooth Pavements
Current research indicates that the pavement smoothness has not significantly changed, and based on increased diesel fuel prices averaging $4.70 per gallon, savings to large trucks increased from $7,989,120 per year in the original study to $14,667,525 per year with increased fuel costs.
MoDOT Pavement Smoothness and Fuel Efficiency 2008 (and today)
Smooth Pavements
** TRIP – September 22, 2010
* WesTrack Facility, Nevada
Conclusion
Well built, economical pavements are not mutually exclusive from ecologically and socially sustainable pavements!
Presented byMatthew J. LaChance
Vanasse Hangen Brustlin, Inc.
Email: mlachance@vhb.com
Questions & Answers
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