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MnDOT Experience withthe Integration Process
Tim Clyne
January 24, 2012
AFK50(2) Subcommittee Meeting
• Luke Johanneck• Shongtao Dai• Lev Khazanovich• Maureen Jensen• Bruce Tanquist
Acknowledgements
• MnPAVEo Many Related Research Projects
• (mostly unbound materials)
• Previous M-E Research Studieso 2004 HMA & PCC Calibrationo Low Temperature Cracking
• DARWin-ME Evaluation• PCC Design Catalogue• Lingering Questions and Issues
Presentation Outline
• Developed in 2001 by Bruce Tanquist
• Currently on version 6.1• Inputs – Climate, Structure
(materials), Traffic• Output – Fatigue Cracking
& Rutting
MnPAVE
• Overlay design module• Reduction in modulus due to cracks• Unsaturated soil properties• Best value granular materials• 5 seasons• Reliability• Statewide hands-on training
MnPAVE Unique Features
• MnDOT Districts use MnPAVE more as comfort level growso Not standard practice yet, but will be in the next
1-2 yearso We developed MnPAVE 10+ years ago, then
paused because MEPDG was coming• State Aid system (cities & counties) use
MnPAVE as standard practice
MnPAVE Use
• Evaluate default inputs• Identify deficiencies in the software• Sensitivity analysis• Evaluate the prediction capabilities of the
MEPDG• Recalibrate performance prediction models
for Minnesota conditions
2004 Calibration for HMA & PCC
• MnPAVE does not address thermal cracking• MEPDG model is OK, but not great• TPF-5(080) and TPF-5(132) improving models
& testing capabilities
Low Temperature Cracking
• Develop Mixture Specificationo Mix Designo Quality Assurance
Fracture Mechanics Approach
ILLI-TC Model
Modeling can provide:• True performance
prediction (cracking vs. time)
• Input for maintenance decisions
• Insight for policy decisions
M-E Evaluation
• 120-day trial periodo Will soon get single user
license• Compared results to
MEPDG v 1.1• Checking past MnROAD
cells
DARWin-ME Evaluation
• 1:1 Inputs• Darwin defaults• MEPDG defaults
• PCC Sensitivity• HMA Runs• MnROAD Mainline
Traffic
DARWin-ME vs. MEPDG
Objective:Develop a design catalogue that further refines
the MEPDG design for a limited number of rigid pavement projects that, taken together, form a basis for all the projects built in the State of Minnesota.• JPCC• Thick Whitetopping (> 6”)
Simplified PCC Design Catalogue
• Basic tiers of traffic levels• Basic regional climate• Shoulder width• Base/subbase type and thickness• PCC mix properties• Joint spacing (12-foot vs. 15-foot)• Drainage• Basic tiers for aggregate coefficient of thermal
expansion
Critical Inputs to Consider
• MnDOT has been conducting many E* testso Intend to incorporate into ME Design
• MnDOT is acquiring IDT test fixture for LTC
Where We’re At
• Still having issues with climate data
General Issues to Resolve
• Stabilized Full Depth Reclamationo Which stabilizer to use?o Bound (pavement)or unbound (base) material?o Should we test E* or Mr?
General Issues to Resolve
• MEPDG is not for the casual user• Not ready yet for deployment• Total cost of ownership
o Calibrate & validate each new version
Barriers to Full Implementation
• Materials & Design “play well” together• Construction personnel (inspectors & contractors)
are the missing link• We don’t do a good job of educating them on
what’s important and why• Our specs may not be set up to achieve the
performance we design for• Enterprise Risk Management
Integration
Tim ClyneMnROAD Operations
Engineer 651-366-5473
tim.clyne@state.mn.us
Questions?
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