Slide 1

Ranking System for Non- Destructive Testing Devices to Assess Quality of HMA during Construction Ahmed Faheem Bloom Companies LLC Dr. Robert Schmitt UW Platteville Dr. Imad Al-Qadi UIUC

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Strategy Define Critical Characteristics of Compaction Identify Non-Destructive Technologies Rank Technologies on Technical Merits, field, portability, training, cost, practicality Goal Investigation and Development of a Non- Destructive System to Evaluate Critical Properties of Asphalt Pavements during the Compaction Process

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Project Stages Stage 1: Determine critical properties Select promising non-destructive testing technologies Stage 2: Field data collection Select field compaction sites Collect data using proposed NDTs Stage 3: Data Analysis Analyze data Evaluate quality of data collected from each NDT

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Background and Stage 1 Objective Non-destructive technologies are emerging Move beyond density and smoothness New measures for characterizing pavement Ability to assess entire pavement sections Real-time data retrieval Objective: Rank NDTs to guide agency selection

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Critical Characteristics Survey of 12 states by Washington DOT (1999)

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Critical Characteristics and Impact Agency-specific rank: #1 #2 #3

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Critical Properties - Characteristics critical to compaction from Lit. Search: 1. Mix segregation 2. In-place compaction 3. Smoothness 4. Temperature segregation 5. Layer thickness 6. Layer bond 7. Pavement modulus - Agency-specific: 1.In-place compaction 2.Temperature segregation 3.Pavement modulus

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Non-Destructive Technologies: Factors to Consider: Operational principle Measures and indicators Test equipment Portability of the test Complexity in the field Time to conduct test Environmental limitations Reliability of collected data Degree of training required Cost States using in practice Available Technologies

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Infrared Thermography Thermal Segregation $30,000 Washington, Texas 25-50F corrective action > 50F suspend, no bonus

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Intelligent Compactor Index, CCV, vibration modulus, stiffness $175,000 to $280,000 (25% above base roller price)

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GPR Thickness, segregation, delamination, ASTM Dry pavement $40,000 to $80,000 (minus vehicle)

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Deflectometers Deflection, stiffness, moduli