Case Study:

1

• Case Study
• Role of the Falling Weight Deflectometer in
  Pavement Rehabilitation Projects
• Michael Frabizzio
• Vahid Ganji, Ph.D., P.E.
• Kaz Tabrizi, Ph.D., P.E.
• Advanced Infrastructure Design, Inc.
• Middlesex, NJ

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Introduction

• Can Play Critical Role in Various Phases of
  Project
• Pavement Evaluation
• Selection of Feasible Rehab Alternatives
• Pavement Design
• Life-Cycle Cost Analysis (LCCA)
• Case Study Project

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Case Study Project (I-295)

• Pavement Improvements Project
• Route I-295 (MP 32 to 41) in New Jersey
• 3 Mainline Lanes, Left Right Shoulders
• Mainline PCC Pavement (78 Slab Length)
• Shoulders AC Pavement

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Pavement Evaluation

• Objectives
• Assess Pavement Condition
• Sectionalize Project Area
• Determine Estimated Repair Quantities
• Various Test Methods
• FWD
• Complements Other Tests
• Provides Realistic Assessment of Pavement System

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Pavement Evaluation

• FWD Data Used to
• Backcalculate Layer Moduli Structural Number
• Assess Condition of Transverse Joints
• Helps to Sectionalize Project Area
• Provide Number Locations of Joints Requiring
  DBR and/or Slab Undersealing

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Pavement EvaluationCase Study

• Coring
• Compressive Strength Testing
• Gradation Analyses
• DCP Testing
• Visual Condition Survey
• FWD Testing
• Review of Ride Quality Surface Distress Data
• Review of Geotechnical Plans Boring Logs
• Review of Construction History Information

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Pavement EvaluationCase Study
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Pavement EvaluationCase Study

• 9 PCC over 12 Subbase
• Southern Fair-to-Poor Northern Good
• Southern Has More Frequent Severe Distresses
• Southern Has Worse Condition PCC Layer
• Relatively Weak Subgrade throughout Project
• Top of Subgrade Better in Northern
• Southern Has Worse Subbase
• Joints in Good Condition throughout Project Area

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Pavement EvaluationCase Study
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Pavement EvaluationCase Study

• 7 AC over 5/7 Gravel Base over 12 Subbase
• Southern Has Slightly Higher SNeff MR Values
• Relatively Weak Subgrade throughout Project Area

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Pavement EvaluationCase Study

• Visual Survey Results Used to Estimate PD FD
  Repair, Slab Replacement, Crack Sealing, Joint
  Sealing Quantities
• FWD Joint Test Results Used to Determine Number
  Locations of Joints Requiring DBR and/or Slab
  Undersealing

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Pavement EvaluationCase Study
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Selection of Feasible Rehab Alt.s

• Determine Which Alternatives Are Practical
  Cost-Effective
• Consider Functional Structural Condition and
  Other Factors
• FWD Other Test Data Are Useful Resources

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Selection of Feasible Rehab Alt.sCase Study

• Typical Alternatives
• Flexible Reconstruction
• Rigid Reconstruction
• AC Overlay
• Rubblization Alternative
• Determine Area with Sufficient Modulus of
  Subgrade Reaction Value

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Selection of Feasible Rehab Alt.sCase Study
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Pavement Design

• All Designs
• MR or k-value Other Inputs Used to Compute
  Required Structural Capacity
• Overlay Designs
• Existing Structural Capacity
• FWD Data Provides MR, k, SNeff Values

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Pavement DesignCase Study

• Backcalculated MR Value for Shoulder Was Used for
  Flexible Reconstruction Rubblization Designs
  for Mainline Lanes
• Backcalculated k-value for Mainline Pavement Used
  for Rigid Reconstruction AC Overlay Designs for
  Mainline Lanes
• Shoulders Designed to Match Profile of Mainline
  Lanes

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Pavement DesignCase Study
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Life-Cycle Cost Analysis

• Provides Life-Cycle Cost Comparison Among Rehab
  Alternatives
• FWD Plays Useful, Indirect Role in LCCA
• FWD Data Used in Various Phases of Project
• Products of These Phases Used in LCCA

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Life-Cycle Cost AnalysisCase Study

• Pavement Designs, Based on FWD Data, Used in LCCA
  for All Alternatives
• DBR Slab Undersealing Quantities, Determined
  Using FWD Joint Test Data, Used in LCCA for AC
  Overlay Alternative

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Life-Cycle Cost AnalysisCase Study
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Summary

• Functions of FWD Data in Pavement Rehab Projects
• Backcalculate Moduli Structural Number
• Assess Joint Condition Determine Joint Repair
  Quantities
• Sectionalize Project Area
• Help Determine Feasible Rehab Alternatives
• Provide Pavement Design Inputs
• Provide Framework Inputs for LCCA
• FWD Is Valuable Tool for These Projects