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?