Darwin-ME Status and Implementation Efforts_IAC9 What s Being Used (7 survey) Asphalt Design: MEPDG Darwin-ME Status and Implementation Efforts Idaho Asphalt Conference October, 9 Does SHA Use or Plan to Use MEPDG DARWIN-ME? Timeframe for Implementation N -1 YES - Using 3 Delaware: Project Analysis Alaska Alaska 7 Survey Hawaii 7 Survey Hawaii 1
Darwin-ME Status and Implementation Efforts_IAC9 Why change?? AASHO Road Test (late 195s) Ottawa, Illinois Design Guide Implementation (AASHO, 191) Team 195s 195s Vehicle Loads... Construction Methods... (AASHO, 191) (AASHO, 191)
Asphalt Thickness (in) Thickness PAVEMENT THICKNESS Asphalt Layer Thickness (in) Darwin-ME Status and Implementation Efforts_IAC9 Limitations AASHTO Loadings Maximum Asphalt layer thickness at the AASHO Road Test? Data Limits (AASHO Road Test) < million Current design traffic is far beyond road test limits AXLE LOAD REPETITIONS Current Designs >1 million 7 5 3 1 1 3 5 7 8 9 1 11 1 13 1 15 1 17 18 AASHO Rod Test Sections Practical Design Aspect (Conceptual) Thickness Distribution of MEPDG Calibration Sections 18 1 1 1 1 1 1 1 8 1 11 1 1 31 3 1 51 5 1 71 7 81 8 91 9 11 1 Section 8 5 7 8 9 1 Relaibility 3
PCC Thickness Thickness 1 1 1 8 PCC Thickness Darwin-ME Status and Implementation Efforts_IAC9 5% Reliability Analysis 18 1 1 1 PCC AASHTo '7 PCC MEPDG Log. (PCC MEPDG ) y =.81Ln(x) -.583 R =.971 Cumulative Differences PCC AASHTo '7 18 PCC MEPDG Log. (PCC MEPDG ) 1 1 y =.81Ln(x) -.583 1 R =.971 + 1 = 8 1 8 5 7 8 9 1 Relaibility 1, 1,, 1,, 1,, 1,,, Traffic (ESALs) to Failure 1, 1,, 1,, 1,, 1,,, Traffic (ESALs) to Failure Big difference in thickness at high ESAL design and exaggerated at high reliability levels MEPDG DARWIN-ME from Research to Reality DARWIN -ME The MEPDG is an analysis tool, not a pavement design program. Training Various Unnamed Sources PMS and Local Calibration Traffic Data Files Engineering Judgment And Policy decisions
Darwin-ME Status and Implementation Efforts_IAC9 Prep-ME Arkansas Software Capabilities: Software Capabilities-Import Raw Data Import Raw Data Traffic Data Check Interpolate Climate and Traffic Data Retrieve Material Data Dynamic Modulus CTE M r Climate: icm files Traffic: AHTD Traffic Monitoring Data Design Guide Implementation 17Team Design Guide Implementation 18Team Software Capabilities-Traffic Data Check Software Capabilities-Materials E* Design Guide Implementation 19Team Design Guide Implementation Team 5
Darwin-ME Status and Implementation Efforts_IAC9 Software Capabilities- Retrieving Data Software Capabilities-Geo-Mapping Utility Design Guide Implementation 1Team Design Guide Implementation Team Software Capabilities-Generated Files Use the experts in your Backyard Arkansas DOT contracted with University of Arkansas Dr. Kevin Hall Indiana DOT contracted with INDOT Research / Purdue University Dr. Tommy Nantung Design Guide Implementation 3Team
Predicted Distress Predicted mean transverse joint faulting, in Darwin-ME Status and Implementation Efforts_IAC9 Indiana DOT HMA Materials Characterization What to Change for Design? Dynamic Modulus District - Nom Max Aggregate Size - 3 Binder Type 3 Binder Characterization 3 Binders DSR data Traffic Data WIM Station Data Analyzed Load Spectra defined by Volume Sensitivity of Inputs for Concrete Parameter Roughness Faulting Permanent Curl/Warp Effective Temperature Difference Percent Slabs Cracked VS VS VS Joint Spacing VS VS VS Dowel Bar Diameter MS MS NS Pavement Thickness S MS VS Modulus of Rupture S NS VS Modulus of Elasticity S NS VS -year/8-day Ratio S NS VS Indiana DOT: MEPDG Guide for Designers Local Calibration Potential All models can be adjusted (Tools, Calibration, Coefs.) Key effect: Eliminate bias of prediction (significant over prediction or under prediction of distress)..3.5..15.1 R =.7 SEE =.5 in N = 3 Statistical Optimization S E rr = (x ip x im ) = Bias 1 1 Make Model Unbiased Possible effect: Reduce residual of prediction (depends on quality of data)..5...5.1.15..5 Measured mean transverse joint faulting, in Bias Measured Distress 7
11/9/ 1/9/ 1/8/7 /7/7 3/9/7 /8/7 5/8/7 /7/7 7/7/7 8//7 9/5/7 1/5/7 11//7 1//7 1/3/8 //8 3/3/8 //8 5//8 /1/8 7/1/8 7/31/8 Rut Depth, mm.e+ 1.E+.E+ 3.E+.E+ 5.E+.E+ 7.E+ 8.E+ Darwin-ME Status and Implementation Efforts_IAC9 A few thoughts on calibration: Step 1: Become comfortable with MEPDG as it stands Step : Does it reflect current pavement performance? Use actual performance data & engineering experience Results from MEPDG will be different than AASHTO 93 Step 3: Is there a bias in MEPDG prediction? Step : Does the MEPDG capture special material properties? OGFC, SMA, Polymer, WMA, Rubber Asphalt, etc Unique Structural Design Good Calibration and Implementation Document Montana DOT http://www.mdt.mt.gov/research/projects/pave/pave_model.shtml Major Findings: Preservation Practice Extend Performance Most models adequate for design Re-calibrate unbound materials rutting S11 As Built Rut Depths Continual Improvement ESALs at Auburn University Continued MEPDG Validation 1. 1. 1. 8.. S11 MEPDG... Date 8
1/1/ 1/18/7 /8/7 8//7 11/1/7 //8 /1/8 9/9/8 1/18/8 3/8/9 Bottom-Up Fatigue Cracking, % of Lane Darwin-ME Status and Implementation Efforts_IAC9 S11 As Built Fatigue Cracking at Auburn University Continued Validation at Auburn University 35 3 MEPDG Measured 5 15 1 5 Date What about Polymers? Looking at Strains Directly Strain Response at Auburn University 9
Percentile Darwin-ME Status and Implementation Efforts_IAC9 1% at Auburn University Training Opportunities 9% 8% 7% % 5% % 3% % 1% Darwin-ME output Average +15-15 N3 3 N 3 N3 N NHI #131 Introduction to Mechanistic Design NHI #13119 - Using Mechanistic-Empirical Pavement Design Guide Software NHI #13 Geotechnical Aspects of Pavements NHI #15118 Application of Traffic Monitoring Guide %. 1.. 3.. 5. Microstrain Previous & On-Going Studies Training / Collaboration Opportunities FHWA Regional WIM/Traffic Workshop Boise, Idaho Sept 9 FHWA Resource Center on request training MEPDG Regional Meetings Look out for DARWIN- ME roll out Summer 1 NCHRP 1-1 Models for Predicting Reflection Cracking of HMA Overlays (8) NCHRP 1-A Models for Predicting Top-Down Cracking of HMA Layers (8) NCHRP 9-9 Simple Performance Tester for Superpave Mix Design (8) NCHRP 9-38 Endurance Limit of HMA Mixtures to Prevent Fatigue Cracking (8) NCHRP 9- Develop Plan for Validating an Endurance Limit for HMA (8) NCHRP 9-A Validating an Endurance Limit for HMA 1
Darwin-ME Status and Implementation Efforts_IAC9 Previous & On-Going Studies Previous & On-Going Studies SHRP Project R-1 Composite Pavement Systems NCHRP 1- Development of AASHTO Pavement Handbook (8) NCHRP 1-7 Sensitivity Analysis of MEPDG (11) NCHRP -3 Characterization of Cementitiously Stabilized Layers for Use in Pavement Design and Analysis (not awarded) Calibration Documents: NCHRP Digest 8, December 3; Refining the Calibration & Validation of HMA Performance Models: An Experimental Plan and Database. NCHRP Digest 83, December 3; Jackknife Testing An Experimental Approach to Refine Model Calibration and Validation. FHWA: Use of PMS data for local calibration. FHWA: Use of deflection basin data in the MEPDG. What is DARWin ME going to look like? Runtime Improvement 35-5 minutes to less than 15 minutes Thickness Optimization Database Structure New GUI Interface Backwards Compatible with earlier MEPDG versions Stand Alone EICM Sensitivity Analysis Enhanced Batch Mode features and reports Structural response output SI Units No Fundamental Theory Changes Perspective Darwin-ME Coming to a computer near you: 19 Completion of Road Test Experiment 191- AASHO Interim Guide of Rigid and Flexible Pavements 197 AASHTO Interim Guide for the Design of Pavements January 11 1981 Revised Chapter III on PCC Pavement Design 198 Guide for the Design of Pavement Structures 1993 Revised Overlay Design Procedures 1998 Supplement to Concrete Design Procedures 11
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