Lightly Surfaced Roads
Transcript of Lightly Surfaced Roads
Lightly Surfaced Roads .
Chuck Jahren and Francis Dayamba
Photo taken by Francis O Dayamba
Motivation
http://www.roadscience.net/services/distress-guide/fatigue-cracking-alligator-cracking
http://www.roadex.org/index.php/permanent7
Presentation Outline
Define Light Surface Treatment Important Factors for success in applying Light
Surface Treatments Outline of treatments discussed in presentation LRRB County Engineer Survey How to strengthen Subgrade/Subbase? LST applied in other regions of the world Alternative to Light Surface Treatment Future Activities Questions and Comments
Define Light Surface Treatment
http://www.sciencedirect.com/science/article/pii/S0921344901000672
Definition: A thin surface treatment of liquid asphalt covered with an aggregate that has an applied thickness of about 0.5-inch or less. -WSDOT
Important Factors for success
Quality of Subgrade and Subbase Experience of contractor Quality of centerline joint and intersections Appropriateness of geometry and pavement
markings
Outline of treatments discussed in presentation
Strengthening of Base Fly Ash Calcium Chloride and
Magnesium Chloride Macadam Stone/Iron-
Mining Products Geogrids and
Geotextile Proprietary Products
Base One Geocells
Light Surface Treatments and Alternatives Chip Seal Otta Seal Slurry Seal Cape Seal RAS and RAP
LRRB County Engineer Survey
Number of Counties
Survey Results
8 Otta Seals
2 Chip Seals
23 None Applied
2 Magnesium Chloride
1 Permazyme
36 total Respondents
LRRB County Engineer Survey
Picture taken by Francis Dayamba Stillwater, MN
Otta Seal
Picture taken by Chuck Jahren Charles Overby and Francis Dayamba TRB, Washington D.C.
1999 Otta Seal Guide Norway-NPRA
LRRB County Engineer Survey
Chip Seal
Pavement Interactive Website “Bituminous surface Treatment”
How to strengthen Subgrade/Subbase?
Fly Ash Base One Macadam Stone Many Proprietary
Products
http://www.stabilisedpavements.com.au/projectM4.html
www.roadsbridges.com/team-effort
How to strengthen Subgrade/Subbase?
CaCl2 and MgCl2 Geogrids and
Geotextiles
http://www.na.fs.fed.us/spfo/pubs/stewardship/accessroads/geotextiles.htm
http://www.tencate.com/TenCate/Geosynthetics/documents/Miragrid/PDS_Miragrid0207.pdf
How to strengthen Subgrade/Subbase?-Geocells
• 100% recycled plastic • Benefits
• Dust reduction • Maintains gravel • Can handle heavy equipment
• Permeable • Cost • Reduced installation time
http://www.geoproducts.org/EnviroGrid-EGA20.aspx
LST applied in other regions of the world Cape Seal
Chip Seal followed by a slurry/micro-surfacing Alleviates cracking and provides smooth/hard-
wearing surface
http://www.cityofsalem.net/Departments/PublicWorks/TransportationServices/Street%20Maintenance/Pages/CapeSeal.aspx
LST applied in other regions of the world Sand Seal
• Emulsion followed by two layers(1/4”-1/2”) of sand/fine(3/8”) aggregate
• Uses • On top of Subgrade • On top of Chip Seal/Otta Seal
• Useful for areas with low supply of stone aggregate and high sand/fine aggregate
• Limited ADT
http://repository.up.ac.za/bitstream/handle/2263/7879/108.pdf?sequence=1
LST applied in other regions of the world Macadam/Iron Mining By-Products
Compacted layer(s) of large stone (Max 4”) Seal Coat on surface Hauling more than 20 miles(uneconomical in Iowa)
http://www.iowadot.gov/operationsresearch/reports/reports_pdf/hr_and_tr/reports/hr175.pdf
Alternative to LST-RAS and RAP
FDR, In-place Recycling, Cold-Mix Asphalt and Hot-Mix Asphalt
Sustainability Cost effective Reduces dust and surface distresses*
*Study by University of Wyoming Department of Civil and Environmental Engineering
http://cait.rutgers.edu/prp/updates-features
Future Activities
Life Cycle Cost Analysis GIS Project Pavement Design
GIS County Map of Minnesota-MnDoT
Conclusions
Many Alternative Light Surface options exist Big Toolbox, choose the right tool for your
application, consider: Available materials and pricing Local Environment conditions Structural Support
Must be applied properly Requires more investment in comparison to gravel But can result in:
Better road user and stakeholder satisfaction Reduced ongoing maintenance costs compared to gravel
THANK YOU!
Questions?