Crumb Rubber LCCA ProjectMichael R. Barr, Jesus M. Garza,
& Duy L. Nguyen
1
Introduction
• Demonstrating LCCA approach of AR
application to highway surfaces
• Determine total economic worth
– Initial and discounted future costs
• LCCA methodology for successful dialogue
– Differential costs of investment options
– Demonstrating sustainable commitment
2
Background
• Scrap Tire Management – a major
economic, environmental and social issue
• Asphalt Rubber – a proven technology and
superior performance product in highway
preservation
• Significance
– Useful, sustainable reclaimed products
– Reduction, management and/or elimination of
EH&S problems
3
Assumptions
Location: Central California, San Joaquin Valley, Visalia, Interstate 5 (I-5)
Project Type: Day Project, Application/Overlay of Rubberized Asphalt Concrete
(RAC) to Highway Surface
Comparison: Application/Overlay of Asphalt Concrete (AC) to Highway Surface
Work Zone: 5-mile stretch, 2-Lanes, Northbound and Southbound (4 Lanes total) =
20 Lane Miles
Material Type: Rubberized Hot Mix Asphalt Concrete (RAC), 2“ overlay to existing
highway surface
Comparison: Conventional hot mix asphalt (AC), 4“ overlay to existing highway
surface
[Note: 2:1 (AC:RAC) Equivalency Factor for resurfacing projects per Caltrans testing]
Options: Application of a Stress Absorbing Membrane (SAM):
Application of a Stress Absorbing Membrane Interlayer (SAMI)
Starting Capital: $10 million
4
Design Alternatives
• AC – Asphat Concrete
• RAC – Rubberized
Asphalt Concrete
• HMA overlay
• HMA mill-and-overlay
• 20 year pavement
design lives
5
Maintenance Options
Stress Absorbing Membrane (SAM)
Consists of a sprayed-on application of
heated straight-run binder, followed by a layer of aggregate chips that are precoatedwith asphalt rubber binder and seated with a rubber-tired roller
Utilizes asphalt rubber binder with 20% rubber
Greatly reduces the incidence of reflective cracking
Stress Absorbing Membrane Interlayer (SAMI)Consists of a SAM with a surface course of either rubberized or conventional hot mix asphalt
Also utilizes asphalt rubber binder with 20% rubber
Is used instead of SAM on high-traffic roads or when extra structural pavement capacity is needed
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Benefits
• Resists Cracking
• Reduces Road Noise
• Environmental Benefits
• Extends of road Surface
• Reduces Hydroplaning
• Cost Effective
$ $ $ $ $7
AC LCCA
8
RAC LCCA
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Results
AC
• Initial Investment = $281,572.00
• Cost (O&M)
Maintenance = $847,616.5
Energy = $689.500.67
• Savings (and or Revenue)
Recycle = $56,508.36
• NPV = $16,683,921.30
• Sustainability details
CO2 Emissions = 773.04 tonnes
Energy = 6.41E+12J
RAC
• Initial Investment = $176,000.00
• Cost (O&M)
Maintenance = $387,695.62
Energy = $344,747.62
• Savings (and or Revenue)
Recycle = $31,017.65
• NPV = $14,350,494.38
• Sustainability details
CO2 Emissions = 375.88 tonnes
Energy = 3.12E+12J
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Results
AC
• Initial Investment = $281,572.00
• Cost (O&M)
Maintenance = $847,616.5
• Savings (and or Revenue)
Recycle = $56,508.36
• NPV = $16,683,921.30
RAC
• Initial Investment = $176,000.00
• Cost (O&M)
Maintenance = $387,695.61
• Savings (and or Revenue)
Recycle = $31,017.65
• NPV = $14,350,494.38
11
Conclusions
Economic Environment Equity
Cost Effective GHG Reduction Reduce Insect Breeding Grounds
Reduces Raw Material Usage
Resource Conservation Reduce Fire Hazards
Speeds Construction Reduce Surface and Ground Water Pollution
Environmental Justice
Reduces Road Maintenance
Renewable ResourceUtilization
Performance Issues (Noise,Vibration, Hydroplaning, Vehicle Splash, Skid Resist.)
Reduces Liability
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Asphalt Rubber: The Sustainability Effect
Recommendations
• When life cycle cost effective, AR overlays
for highway resurfacing typically yield 10-
25% cost savings
• Project’s limited scope: consider design
alternatives for optimization.
13
References
• Cooper, S. J. (2011, October). Asphalt pavement recycling with
reclaimed asphalt pavement (rap). Nwpma, 18th annual fall pavement
conference, Portland, OR.
• Entech asphalt rubber. (2010). Retrieved from
http://www.4entechasphaltrubber.com/about_asphalt_rubber.html
• Keches, C., & LeBlanc, A. (2007). Reducing greenhouse gas emissions
from asphalt materials. Unpublished manuscript, Science, Worcester
Polytechnic Institute ,
• Roschen, T. (n.d.). Asphalt rubber. Informally published manuscript, ,
Available from CalRecylce. Retrieved from www.calrecycle.ca.gov/
• rubberized asphalt concrete (rac) benefits. (2011, August 25).
Retrieved from http://www.calrecycle.ca.gov/tires/rac/Benefits.htm
• Shatnawi, S. (2012). Life-cycle cost analysis of flexible pavement
systems rehabilitated with the use of asphalt rubber interlayers.
Informally published manuscript,
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