Civil and Environmental Engineering Department by nikeborome

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									      Data Collection for Determining
           Pavement Condition
•   Friction
•   Profile
•   Rut Depth
•   Structure
•   Distress identification
        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
        Friction-Locked Wheel
• ASTM 261
  – Standard Tire
  – Water on surface
  – 40 MPH
Friction tester- Locked Wheel
                Friction Tester
                    Spin up
• Wheel Lowered at 40 MPH
  – Friction force=torque/tire radius
  – f= Friction Force / Weight
  Better then Locked Wheel as less equipment is
    required
Spin Up Friction Tester
         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
Road Surface Analyzer
     Roughness Measuring

Rod and Level
Dipstick profiler
Road roughness Meter
Profiling Devices
       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= 1000*ARS
      PSR  5e0.18( IRI )
                      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.
Profilograph
               Profiling Devices
•   Straight Edges
•   Low Speed Systems
•   Inertial Reference Systems
•   Can determine
    – Transverse Profile
    – Longitude Profile
    – Pavement Texture
Ames Engineering LISA
         Laser RST
Road Roughness Measurement
                Rut Depth
• Uses many of the Standard Road Profilers
• Uses transducers to measure differences in
  elevation between wheel paths and center of
  road
Rut Depth
            Distress Surveys
• Automatic and Continous
• High Speed Digital Images
• Used At Speeds Up to 60 MPG
      Dynatest
Video Distress Vehicle
           Structural Evaluation
•   Falling Weight Deflectometers
•   Dynaflect Dynamic Force Generator
•   Benkleman Beam-Deflection Basin
•   Ground Penetrating Radar
        Structural Test
Falling Weight Deflectometer
       Dynaflect
Dynamic Deflection System
Benkleman Beam
Ground Deflection
       Roadscan
Ground Penetrating Radar

								
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