at Auburn University National Center for Asphalt Technology Accelerated Pavement Testing Facilities “APT”

at Auburn University National Center for Asphalt Technology 2 “… the controlled application of wheel loading to pavement structures for the purpose of simulating the effects of long- term in-service loading conditions in a compressed time period (Hugo and Martin, 2004).” Accelerated Performance Testing

at Auburn University National Center for Asphalt Technology 3 “… the controlled application of wheel loading to pavement structures for the purpose of simulating the effects of long- term in-service loading conditions in a compressed time period (Hugo and Martin, 2004).” Accelerated Performance Testing

at Auburn University National Center for Asphalt Technology 4 Accelerated Performance Testing Full Scale Test Tracks Load Simulation Devices

at Auburn University National Center for Asphalt Technology 5 Full Scale Test Tracks Bates Experimental Road ( ) Solid Rubber Tires WASHO Road Test ( ) Post War Truck Loads AASHO Road Test ( ) Varying Loads and Buildups Mn/ROAD (1994-present) Load Limits on Spring Thaw (& Mechanistic Response) Westrack ( ) Superpave Design (& Performance Specifications) NCAT Track (2000-present) Mix & Structural Performance

at Auburn University National Center for Asphalt Technology 6 AASHO Road Test

at Auburn University National Center for Asphalt Technology 7 ASPHALT surface CRUSHED STONE base SANDY GRAVEL subbase MATERIALTHICKNESS 0 10” 20” AASHO Road Test

at Auburn University National Center for Asphalt Technology 8 WesTrack

at Auburn University National Center for Asphalt Technology 9 Actual Truck Traffic

at Auburn University National Center for Asphalt Technology 10 Load Simulation Devices U.K. Transport Research Laboratory’s “Road Machine” (1912) Asphalt Mixes over Concrete U.K. Road Research Laboratory’s “Road Machine 2” (1933) Heavy Vehicle Simulator Prototype (1960s) South African Remote Roadway Methods Danish Road Testing Machine (1973) Full- Scale Indoor Facility with Water Control Accelerated Loading Facility (1983) Australian Low Cost Paving Alternatives French Nantes Carousel (1984) Spain’s CEDEX Oval (1988)

at Auburn University National Center for Asphalt Technology 11 UK “Road Machine”

at Auburn University National Center for Asphalt Technology 12 LA Pavement Research Facility

at Auburn University National Center for Asphalt Technology 13 Laboratory Scale Simulators

at Auburn University National Center for Asphalt Technology 14 Surface Performance

at Auburn University National Center for Asphalt Technology 15 Evaluating Alternatives

at Auburn University National Center for Asphalt Technology 16 Specific Model Calibration

at Auburn University National Center for Asphalt Technology 17 General Model Calibration

at Auburn University National Center for Asphalt Technology s - Stresses and deformations via multi-layered analysis –1962 – 1 st International Conference on the Structural Design of Asphalt Pavements (AASHO) –1967 – 2 nd International Conference on the Structural Design of Asphalt Pavements 1970s - Rutting via layer strains –1972, 1977 – 3 rd and 4 th International Conference on the Design of Asphalt Pavements –1976 – Symposium on Rutting in HMA Pavements by TRB 1980s - More sophisticated visco-elastic, nonlinear models –1982, 1987 – 5 th & 6 th International Conference on the Design of Asphalt Pavements 1990s - Research implementation & rutting prediction –1992, 1997 – 7 th & 8 th International Conference on the Design of Asphalt Pavements –1999 – 1 st International Conference on Accelerated Pavement Testing –2002 – Symposium for the 2000 NCAT Pavement Test Track 2000s - Comprehensive mechanistic pavement design –2004, 2008 – 2 nd & 3 rd International Conference on Accelerated Pavement Testing –2005, 2009 – Symposium for the 2003 & 2006 NCAT Pavement Test Track Modern Evolution of APT

at Auburn University National Center for Asphalt Technology 19

at Auburn University National Center for Asphalt Technology 20

at Auburn University National Center for Asphalt Technology 21

at Auburn University National Center for Asphalt Technology 22

at Auburn University National Center for Asphalt Technology 23

at Auburn University National Center for Asphalt Technology 24

at Auburn University National Center for Asphalt Technology 25

at Auburn University National Center for Asphalt Technology 26

at Auburn University National Center for Asphalt Technology 27

at Auburn University National Center for Asphalt Technology 28

at Auburn University National Center for Asphalt Technology 29

at Auburn University National Center for Asphalt Technology 30

at Auburn University National Center for Asphalt Technology 31 NCAT Research Objectives Optimize thickness design (structural) Identify ideal materials & methods (mix)

at Auburn University National Center for Asphalt Technology 32 NCAT Pavement Test Track

at Auburn University National Center for Asphalt Technology Research Cycle (T4)

at Auburn University National Center for Asphalt Technology 34 Pavement Condition Data Rutting Roughness Texture Density Cracking Permeability Noise Friction Reflectivity High-speed response

at Auburn University National Center for Asphalt Technology Rutting (SBS vs GTR Mill/Inlay) 35

at Auburn University National Center for Asphalt Technology 36 Texture (Pavement Preservation)

at Auburn University National Center for Asphalt Technology Roughness (Soft Clay Perpetual Pvmt) 37

at Auburn University National Center for Asphalt Technology High-Speed Pavement Response 38

at Auburn University National Center for Asphalt Technology 39 Perpetual Pavement on Soft Clay 14” pavement looks great after 17 million ESALs 10” pavement recently rehabilitated for 2 nd time –In need of 1 st rehabilitation after 10 million ESALs –5” mill/inlay failed again after 3½ million ESALs –2½ million ESALs on 5¾ inch high polymer inlay

at Auburn University National Center for Asphalt Technology Thin Perpetual Pavements inch perpetual (original) Track foundation24 inch perpetual (original) Track foundation Designed with ‘93 Guide for MANY cyclesDesigned with ‘93 Guide for MANY cycles Two 9 inch thick structural sections in 2003 ‘93 Guide predicted failure near 10M ESALs‘93 Guide predicted failure near 10M ESALs 27M ESALs to date (perpetual expectation)27M ESALs to date (perpetual expectation) 15 inches of wasted (excess) thickness? 14 inches required on N9 soft subgrade14 inches required on N9 soft subgrade

at Auburn University National Center for Asphalt Technology Optimized Structural Design 41 Technology has improved since AASHO Road TestTechnology has improved since AASHO Road Test Need to recalibrate coefficients for interim useNeed to recalibrate coefficients for interim use Increase from 0.44 to 0.54 via all Track dataIncrease from 0.44 to 0.54 via all Track data 18.5 percent thinner structural designs18.5 percent thinner structural designs Alabama saving $25M annually

at Auburn University National Center for Asphalt Technology 42 PFC Surface Cracks (Tack Method) 2006 crack susceptible dense Superpave mix –Surface cracks after 1.9M ESALs (Rehab at 5.6M) 2009 PFC surface placed with conventional tack –Surface cracks after 2.2M (cracking/pumping at 7M) 2009 bonded PFC surface placed with spray paver –Surface cracks after 4.1M (looks pretty good at 7M)

at Auburn University National Center for Asphalt Technology 2009 Group Experiment (+) 43

at Auburn University National Center for Asphalt Technology Group Experiment (+)

at Auburn University National Center for Asphalt Technology 45 GE Strain Response 50% RAP Virgin Mixes

at Auburn University National Center for Asphalt Technology 46 Laboratory Beam Fatigue Results

at Auburn University National Center for Asphalt Technology 47 Beam Fatigue Results Axles Passes per Research Cycle

at Auburn University National Center for Asphalt Technology 48

at Auburn University National Center for Asphalt Technology Web Performance Reports 49

at Auburn University National Center for Asphalt Technology 50 WMA Certification Program

at Auburn University National Center for Asphalt Technology Profiler Certification Program 51

at Auburn University National Center for Asphalt Technology 52 Questions ?