Data Collection for Determining Pavement Condition

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Data Collection for Determining Pavement Condition

• Friction
• Profile
• Rut Depth
• Structure
• Distress identification

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Friction Determination

• Importance
• Inadequate friction leads to higher number of
  crashes
• Required to provide a safe road
• Can be used to evaluate materials-AWI
• Evaluated as
• Locked Wheel
• Spin Up Test
• Surface Texture Measurement

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Friction-Locked Wheel

• ASTM 261
• Standard Tire
• Water on surface
• 40 MPH

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Friction tester- Locked Wheel

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Friction TesterSpin up

• Wheel Lowered at 40 MPH
• Friction forcetorque/tire radius
• f Friction Force / Weight
• Better then Locked Wheel as less equipment is
  required

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Spin Up Friction Tester
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Road Surface Analyzer

• A laser-based profiler using an accelerometer
• established inertial reference.
• ROSAN measures texture and longitudinal pavement
  profile at highway speeds.
• Texture Analysis - Determination of Mean Profile
• Depth Smoothness Analysis - ?? Roughness Analysis
  - Determination of International
• Roughness Index (IRI) Ride Number (RN), using
• ASTM E 950 E 1926

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Road Surface Analyzer
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Roughness Measuring

• Rod and Level
• Dipstick profiler
• Road roughness Meter
• Profiling Devices

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Roughness Measurement

• Present Serviceability Rating (PSR)
• Based on ride quality defined by observer
• Values from 1-5
• International Roughness Index
• Based on Average Rectified Slope (ARS) determined
  from vehicle accumulated suspension motion
  divided by the distance m/km
• IRI 1000ARS

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Dipstick Analyzer

• Operation The Dipstick Road Profiler stands on
  two support legs.  The operator simply "walks"
  the Dipstick along a survey line alternately
  pivoting the instrument about each leg. Two
  digital displays show the elevation difference
  between the Dipstick's two support legs.
  Audible and visual signals alert the operator
  when each elevation difference reading is
  measured and automatically recorded.  

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Profilograph
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Profiling Devices

• Straight Edges
• Low Speed Systems
• Inertial Reference Systems
• Can determine
• Transverse Profile
• Longitude Profile
• Pavement Texture

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Ames Engineering LISA
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Laser RSTRoad Roughness Measurement
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Rut Depth

• Uses many of the Standard Road Profilers
• Uses transducers to measure differences in
  elevation between wheel paths and center of road

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Rut Depth
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Distress Surveys

• Automatic and Continous
• High Speed Digital Images
• Used At Speeds Up to 60 MPG

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DynatestVideo Distress Vehicle
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Structural Evaluation

• Falling Weight Deflectometers
• Dynaflect Dynamic Force Generator
• Benkleman Beam-Deflection Basin
• Ground Penetrating Radar

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Structural TestFalling Weight Deflectometer
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DynaflectDynamic Deflection System
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Benkleman BeamGround Deflection
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RoadscanGround Penetrating Radar