Overview. What is a Perpetual Pavement? Design Concept. PerRoad Pavement Design Software. Design Against Deep Structural Problems

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1 PerRoad Pavement Design Sotware SEAUPG Annual Meeting Nashville, TN December 13, 2 Overview Perpetual Pavements Deined Design Principles Design Sotware PerRoad 2.4 Case Study Bin-Bo Expressway, Shandong China Dr. David H. Timm, P.E. Auburn University / National Center or Asphalt Technology What is a Perpetual Pavement? Design Against Deep Structural Problems Long lie (+ Years) Minimum maintenance / rehabilitation Surace distresses only Stresses in Asphalt Concrete Horizontal Stress/Strain Shear Stress/Strain Vertical Stress/Strain C } Design Concept 4 Zone to O High 6 Compression SMA, OGFC or Superpave High Modulus Rut Resistant Material (Varies As Needed) T Max Tensile Strain Flexible Fatigue Resistant Material 3-4 Pavement Foundation Pavement Foundation December 12, 2 1

2 Design Criteria Fatigue Threshold Limit Bending to < 6µε (Monismith, Von Quintus, Nunn, Thompson) Thick HMA (> 8 ) Base (as required) Subgrade Limit Vertical Compression to < 2µε (Monismith, Nunn) Strain, (1E-6) Normal Range or Fatigue Testing Endurance Limit E+8 Number o Loads to Failure Normal Fatigue Testing Results Versus Endurance Limit Testing Pavement Design Parameters Material Characterization Traic Conditions Composition Current volume Growth Environmental Conditions Variability Traditional M-E Design Log ε Log N Perpetual Pavement Design Log ε Probabilistic Design Monte Carlo Simulation Axle Weight Log N No Damage Accumulation Threshold Strain Material Properties Monte Carlo Random Sampling Mechanistic Model % Below Threshold % Above Threshold Thickness Pavement Response December 12, 2 2

3 Design Sotware: PerRoad 2.4 Sponsored by APA Developed at Auburn University / NCAT M-E Perpetual Pavement Design and Analysis Tool Structural Inputs Seasons Layer Properties Perormance Criteria Load Spectra Axle Types Location Criteria Threshold Transer Functions Distribution o Loads Axles / 1 Heavy Axles Rural Interstate Rural Principal Arterial 2 Rural Minor Arterial Rural Major Collector Rural Minor Collector Rural Local Collector 1 Urban Interstate Urban Other Freeways and Expressways Urban Principal Arterial 1 Urban Minor Arterial Urban Collector Axle Group Weight, kn Axles / 1 Heavy Axles Axle Group Weight, kn Rural Interstate Rural Principal Arterial 3 Rural Minor Arterial Rural Major Collector 2 Rural Minor Collector Rural Local Collector 2 Urban Interstate Urban Other Freeways and Expressways Urban Principal Arterial 1 Urban Minor Arterial Urban Collector December 12, 2 3

4 PerRoad Output Axle Group Weight, kn Axles / 1 Heavy Axles Rural Interstate Rural Principal Arterial Rural Minor Arterial Rural Major Collector Rural Minor Collector Rural Local Collector Urban Interstate Urban Other Freeways and Expressways Urban Principal Arterial Urban Minor Arterial Urban Collector Case Study: Bin-Bo Expressway Binzhou, China Chinese Pavements - Background Standard design is HMA over semi-rigid base Marshall mix design SMA surace mixtures High percentage o overloads Some issues: Cracking Water damage Rutting Early pavement ailures very common PCC: 6 8 Years HMA: 3 Years GOAL: Design and Build a pavement that will last! Project Location Construction Site Shandong Province Population: 9 Million June, 2 November, 24 December 12, 2 4

5 Load Spectra Shandong Traic Data 1% 9% Percent o Axles Less Than 8% 7% 6% % 4% 3% 2% 1% Average Values Steer Single Tandem Tridem % % 9% Axle Weight Distribution Comparison Test Sections Axle Load Percentile 8% 7% 6% % 4% 3% 2% U.S.-Single U.S.-Tandem China-Single China-Tandem 1. Shandong DOT control section 2. South China design control section 3. 2 ull depth HMA Conservative threshold o 7 µε 4. 1 ull depth HMA Relaxed threshold o 12 µε. 1 ull depth HMA with higher quality materials 1% % Axle Group Weight (1, lb) Designed using PerRoad and Chinese Load Spectra Shandong Control Section Alternative Chinese Design Depth, in HMA 14 Stabilized Granular SMA, 1.6 HMA-AC2, 2. HMA-AC2, 2.4 Stabilized Granular, 7.1 Stabilized Granular, 7.1 Depth, in South China Pavement Design - Existing 8. HMA HMA, 1.6 HMA, 3.1 HMA, 3.9 Asphalt Treated Base, 3.9 Cement Treated Base, 9.1 Granular Base, Stabilized Soil Stabilized Subgrade, One Size Aggregate, December 12, 2

6 7 µε Design 12 µε Design 2 inch Full Depth Perpetual Design 2'' SMA 3'' 19mm 4.2'' 2mm 1'' Full Depth HMA 2'' SMA 3'' 19mm 4.2'' 2mm Depth, in '' 2mm 3.'' OGDL Depth, in '' OGDL 3'' 12.mm Fatigue 2 3'' 12.mm Fatigue Instrumentation Plan Instrumentation Array Axle Sensors Outside Wheel Path Temperature Strain Gage 2 kpa Pressure Cell Instrumentation Layout December 12, 2 6

7 U.S. Beneits Instrumented perpetual pavements 3 µε Live traic dynamic data Investigate eects o overloads on pavement response and perormance Evaluate variety o designs PerRoad Update New version (3.) to be released in 26 Continue training seminars PerRoad 2.4 available at: December 12, 2 7