Building MEPDG PDG Climate Files Dr Michael H el Heitzman PE NCAT, Aubur NCAT, Aubur burn University burn University Dr Gene ene Takle Climate Science Program ram, Iowa State University Climate Science Program 1 Iowa State University
In this prese resentation…. � Why is climate input import portant � Building historic climate file files � Building future climate files files � Impact on predicted pavem vement performance Climate Science Program 2 Iowa State University
Pavement Desi Design Variables Each load application P PCC Modulus CTB Modulus Traffic HMA Modulus Modulus Granular Base Modulus Subgrade Modulus 0 2 4 6 8 Time, ye , years Climate Science Program 3 Iowa State University
Permenant Deformation: Total Rutting g in Pavement Layers (inch) 0.70 Predicted Predicted Ac Rutting Design Value = 0.25" 90% Relia 90% Relia Reliability Reliability 0.60 Rutting Rutting Design Limit Design Limit 0.50 um Rutting (inch) SubTotalAC 0.40 SubTotalGB Total Total SubTotalSG Total Rutting Total Rutting Maximum 0.30 TotalRutReliability HMA HMA 0.20 0.10 Subg Subg ubgrade ubgrade Aggr. Base Aggr. Base 0.00 0 18 36 54 72 90 108 126 144 162 180 198 Pavement age, month Climate Science Program 4 Iowa State University
Only 12 MEPDG climate files in M in Mississippi � 4 sites with 5-6 years of clim climate data (very limited) � 8 with 8-10 years of climate ate data (limited) � Starting with mid 1990s
Ames Tempera perature Trends Climate Science Program 6 Iowa State University
Iowa Averages a es and Extremes Decade Avg High A Avg Low 100°+ events (days / weather station) 1970s 1970s 58.9 58.9 37.4 37.4 6 6 1980s 59.6 38.1 21 1990s 58.4 38.3 2 What 10-year period od do you want to use for pavement perform ormance prediction? Climate Science Program 7 Iowa State University
Developm lopment of Climate Data ata Input Files for the M he MEPDG � Build complete 40-year hist historic climate files from county measurements � Build 40-year future climate ate files from global and regional models Climate Science Program 8 Iowa State University
ASOS/AWOS OS COOP Climate Science Program 9 Iowa State University
Ana nalysis Grid Gri Grid Node Neighbor Interpolation Climate Science Program 10 10 Iowa State University
Climate Science Program 11 11 Iowa State University
Complete Historic Files Files Mississippi County Weather Locations 35.5 35 � 40-year files (1970-2010) 34.5 34 � Each county in the State (82 (82) 33.5 33 latitude 32.5 32.5 lat 32 31.5 31 30.5 30 -92 -91.5 -91 -90.5 -90 -89.5 -89 -88.5 -88 longitude Climate Science Program 12 12 Iowa State University
How should future cl climate files be built? Climate Science Program 13 13 Iowa State University
GLOBAL AL MODEL 35,000 sq-mi patte attern Includes: solar ra radiation & green house gasses cha changes Frequency: 6 hou ours over 10 years Contemporary Future Scenario Scenario (decade of 1990s) (decade of 2040s) REGIONA NAL MODEL 1200 sq-mi patte attern Includes: region Includes: region ional geographic ional geographic features and clim climate patterns Frequency: 3 m minutes Monthly Climate “DELTA LTAs” (for 50-year period) Temperature DELTA = Future Scenari ario – Contemporary Scenario Precipitation DELTA = Future Scenari ario / Contemporary Scenario Climate Science Program 14 14 Iowa State University
Climate Science Program 15 15 Iowa State University
Average Month thly Temperature Climate Science Program 16 16 Iowa State University
Temperature re Distribution Climate Science Program 17 17 Iowa State University
Average Month nthly Precipitation Climate Science Program 18 18 Iowa State University
50-year D r DELTA’s JAN FEB MAR APR MAY JU JUN JUL AUG SEP OCT NOV DEC T [C] 1.3 1.5 3.2 2.4 2.7 1. 1.9 2.8 2.0 1.7 1.9 2.0 1.4 P [%] -21 -13 40 14 39 1 13 -17 17 68 -20 37 -11 1970-2010 Historic DELTA Climate ( per ( per month) 2010-2050 Virtual Climate
What is the imp e impact of more accurate clim e climate files? 9.3-in JPCP 12.5-in H in HMA 4.5-in HMA, AC-30 20 ft joint spacing AC-30 3.0-in AC perm base tied PCC shoulder 12-in A-2-4 base 5.7-in lime stab base A-6 subg ubgrade A-2-4 subgrade A-2-4 subgrade 8-in lime stab subgrade A-6 subgrade Climate Science Program 20 20 Iowa State University
Complete Historic Files Files Mississippi County Weather Locations 35.5 � 40-year files (1970-2010) 35 34.5 � Each county in the State (82 (82) 34 33.5 Critical for calibration 33 latitude 32.5 32.5 lat 1985-2000 pavement 32 � 5-yr MEPDG climate 31.5 31 1995-2000 climate (3x) 30.5 � HISTORIC climate 30 -92 -91.5 -91 -90.5 -90 -89.5 -89 -88.5 -88 1985-2000 climate longitude Climate Science Program 21 21 Iowa State University
Complete Future File Files � 40-year climate files � each climate region (10) Critical for predicting performan Critical for predicting performan ance ance 2010-2030 design � 5-yr MEPDG climate 1995-2000 climate (4x) � FUTURE climate 2010-2030 virtual climate Climate Science Program 22 22 Iowa State University
PVMT PAVEMENT CLIMATE Mississippi Climate Zone TYPE PERFORMANCE COMPARISON 1 2 3 4 5 6 7 8 9 10 PCC FAULT MEDPG-Historic MEPDG-Virtual Historic-Virtual PCC RIDE MEDPG-Historic MEPDG-Virtual Historic-Virtual HMA1 RUTTING MEDPG-Historic S S S S S MEPDG-Virtual S S S S Historic-Virtual Historic-Virtual HMA1 RIDE MEDPG-Historic S MEPDG-Virtual S Historic-Virtual HMA2 RUTTING MEDPG-Historic S S S S S S S MEPDG-Virtual S S S S S Historic-Virtual HMA2 RIDE MEDPG-Historic S S S S S MEPDG-Virtual S S S S S Historic-Virtual Climate Science Program 23 23 Iowa State University
9.3-in J in JPCP Faulting (M-H) Faulting (H-V) 0.05 0.05 0.045 0.045 0.04 0.04 0.035 n g ( in ) 0.035 g ( in ) 0.03 0.03 0.03 0.025 0.025 F a u lt in g F a u lt in g 0.025 0.025 0.02 0.02 0.015 0.015 0.01 0.01 0.005 0.005 0 1E-17 -0.005 -0.005 -0.01 -0.01 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 Zones Zones Climate Science Program 24 24 Iowa State University
12.5-in in HMA Rutting (H-V) Rutting (M-H) 0.25 0.25 0.2 0.2 n g ( in ) g ( in ) 0.15 0.15 R u t t in g R u t t in g 0.1 0.1 0.05 0.05 0 M-V Zone(1-10), 0 -0.05 -0.05 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 Zones Zones Climate Science Program 25 25 Iowa State University
4.5-in H in HMA Rutting (M-H) Rutting (H-V) 0.25 0.25 0.2 0.2 g ( in ) g ( in ) 0.15 0.15 0.15 0.15 R u t t in g ( R u t t in g ( 0.1 0.1 0.05 0.05 0 0 M-V Zone(1-10), -0.05 -0.05 1 2 3 4 5 6 7 8 9 10 1 2 3 4 5 6 7 8 9 10 Zones Zones Climate Science Program 26 26 Iowa State University
Zone 4 Ruttin ting Thin HMA MEPDG HIST VIRT 1.2 1 nches) 0.8 rutting (inc 0.6 0.4 0.2 0 1 61 121 181 241 301 361 421 tim time (months) Climate Science Program 27 27 Iowa State University
Historic v MEPDG (W (Wash Co - thin HMA) MAX-historical MAX-MEP EPDG AVG-Historical AVG-MEPDG 110 100 90 Max Temp 80 70 70 Monthly M 60 50 40 30 0 10 20 30 40 40 50 60 70 80 90 month (MEPDG 8/99 9 - 6/05)(Historical 8/70 - 12/76) Climate Science Program 28 28 Iowa State University
Current MEPDG 10-year climate fi files may adversely impact pavement performance predictio ctions � The fix is accurate and impro roves MEPDG model calibration Future climate may be different fro from historic climate and change pavement performance predictio ctions � There are accepted scientific fic models to build future climate files Climate Science Program 29 29 Iowa State University
Building MEPDG DG Climate Files Dr. Michael H el Heitzman, PE NCAT, Auburn burn University mah0016@a 6@auburn.edu Dr. Gene ene Takle Climate Science Program ram, Iowa State University gstakle@ia @iastate.edu Climate Science Program 30 30 Iowa State University
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