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
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