April 2006

1. Forensic Analysis of Asphalt BindersForCAPA “Quality Assurance of Asphalt Binders”Ken GrzybowskiPRI Asphalt Technologies, Inc.Tampa, Florida April 2006

2. PRI  Plant Mixing Difficulty in HMA Compaction Pavement Quality Rutting / Shoving Raveling / Lack of Adhesion Cracking Forensics - Where Used

3. PRI Where to Check – The ObviousBinder Storage Tanks Temperature Correct?Thermometers working, calibrated? “Heater” and recirculation pumps working? Right Product in Tank?  Samples Retained (makes life much easier)? Sample representative? PLANT MIXING(‘binder does not coat’)

4. PRI Where to Check – The ObviousStockpiles & JMF Aggregates Dry?Feed Rates Proper?Asphalt Binder JMF Aggregate Blend Lime (if used) Asphalt Binder % per JMF? PLANT MIXING(‘binder does not coat’)

5. PRI Where to Check – Not So ObviousAsphalt TankLow Temperature(higher viscosity = reduced flow) Heating Coils / Fire Tubes ‘Coked’‘Buried’ (common w/ some GTR blends) High Temperature (lower viscosity = ‘higher’ flow & less weight) Recirculation pumps / agitators not working Temperature controls not properly workingSensor PLANT MIXING(‘binder does not coat’)

6. PRI Where to Check – Not So ObviousAsphalt TankAsphalts will layer (larger tanks more susceptible)Different grades or sources = different SG’s possiblyHeat Transfer Fluid LeakYields a more fluid binder / lower viscosity PLANT MIXING(‘binder does not coat’)

7. PRI Where to Check – Not So ObviousAsphalt TankOverheatingTank open to atmosphereVolatiles loss = stiffer binder / higher viscosity(a prime reason most binders age in-the-tank) Tank closedAsphalt ‘cracks’ = more fluid binder / lower viscosity PLANT MIXING(‘binder does not coat’)

8. PRI Where to Check – Not So ObviousPoor Coating VisibleAggregate DryingMoist aggregate Easy Solution – first place to look Burner FuelKnow the fuel (purchase specs?) Incomplete combustion Does not take much – difficult to detect Fuel Leak Does not take much – difficult to detect PLANT MIXING(‘binder does not coat’)

9. PRI  Poor Density & Workability Incorrect Compaction Process for Mix (obvious) Low HMA Temperatures Wrong Binder Insufficient or Too Much Binder Contaminated Binder Contaminated Mixes Moist aggregate Truck Bed Release (TBR) ‘ends up’ in binder COMPACTION DIFFICULTIES

10. PRI  Rutting / ShovingWrong Binder Too much Binder Contaminated Binder Poor Aggregate Skeleton or JMF Contaminated Mix Moist aggregate Truck Bed Release (TBR) ‘ends up’ in binder PAVEMENT QUALITY

11. PRI  Raveling / Lack of AdhesionIncorrect Binder (anti-strip?) Insufficient Binder Contaminated Binder Improper Aggregate Gradation Contaminated Mix Burner Fuel Moist aggregate Truck Bed Release (TBR) ‘ends up’ in binder Poor Compaction PAVEMENT QUALITY

12. PRI  CrackingInsufficient Binder Contaminated Binder Improper Aggregate Gradation Contaminated Mix Burner Fuel Moist aggregate Truck Bed Release (TBR) ‘ends up’ in binder Pavement System Design and Architecture PAVEMENT QUALITY

13. PRI  Define the ProblemNature and extent (what’s changed?) People Process Materials Application Combinations of the above Forensic Basics (where to start)

14. PRI  Most (but not always) problem originates with peopleSimple mistakes / lack of attention to details Must admit you have a problem Ask obvious questions of those involved Saves time, money and wasted effort Align your facts and information Learn from previous mistakes (remembered?) Mistakes tend to repeat Forensic Basics (what you already know)

15. PRI  Tank or Purchased Products Compare to Specifications PG, Pen or Viscosity AASHTO, ASTM or Agency Specification Evaluate for Composition Polymer Type & Content (SBS, SBR, EVA, Others) Additives (Acid, Bases, A-S’s, Cross-Linkers, etc) Contaminates (Fuel Oils, Used Motor Oil, Distillates, etc.) Forensics – Our Binder Capability

16. PRI  Plant / Loose Hot MixExtract and Recover Binder & AggregateRequires experience and knowledge Extraction & recovery process may change binder properties Compare recovered binder to Specifications Laboratory must have ‘complete’ capability PG, Pen or Viscosity (AASHTO, ASTM or Agency Specification) Evaluate for Composition Polymer Type & ContentAdditives (diluents, etc)Contaminates (burner fuel, moisture, etc.) Forensics – Our Binder Capability

17. PRI  Sample / Core Pavement PlanSufficient & representative samples to evaluate and assess per plan Agencies may define Use industry accepted practices  Documented Plan Sample labels, weights, measures & photos Lift / layer labels, weights, measures & photos Forensics – Pavement Analysis

18. PRI  Two Step Evaluation Process1st Step (may option to jump to 2nd Step) ‘Non-Destructive’ Testing focused at problem(are there specs for comparison??) Performance Properties, a few examples Resilient Modulus, IDT, Permeability Physical Properties Volumetrics Forensics – Pavement Analysis

19. PRI 2nd Step, - Destructive TestingExtract and Recover Binder & Aggregates Requires experience and knowledgeExtraction & recovery process may change binder properties Reflux Extraction = ‘bad’ Solvent selection critical (may change binder properties) Recovery by D5404 or D1856 (Abson) are musts PreferredASTM D2172, Centrifuge preferred w/ toluene ASTM D5404, Roto-Vap Recovery Forensics – Pavement Capability

20. PRI  Recovered Binder AnalysisCompare recovered binder to specifications & requirements, concentrate on defined problem PG, Pen or Viscosity, Other or select properties AASHTO, ASTM or Agency Specifications Evaluate for Composition (analytical techniques) Polymer Type & Content  Additives (diluents, A-S’s, etc) Contaminates (burner fuel, distillates, moisture, etc.) Forensics – Pavement Capability

21. PRI  Recovered AggregatesInvestigate for specification compliance Consensus properties JMF gradation Contaminates Forensics – Pavement Analysis

22. PRI  Determine the ‘story’Each bit of data fits in (sum of parts = whole) Materials JMF Architecture & Specifications Construction Performance Properties Forensics – Pavement Analysis

23. PRI  What we can determineBinder’s specification compliance As neat binder or recovered from loose or compacted HMA’s (field aged) Binder’s Composition Type and quantity of polymer, additive or other To a degree if binder was straight run or ‘engineered’ Presence of Contaminates Today’s Capabilities

24. PRI  What we can determineMix Design Compliance Conventional (Marshall, Hveem) and Superpave Mix Performance Properties On lab and field samples On lab aged specimens (emerging technology) Aggregate Properties Pavement Architectural Soundness Today’s Capabilities

25. PRI  Conflict Resolution Problem Solve Improve Materials and Process Improve Performance Advance the Technology Why?

26. PRI  Conflict Resolution No Specifications Empirical or Subjective Specifications Prescriptive Specifications  Reluctance to changeInvestigation Cost vs. Job / Problem ValuePlace the Blame Issues

27. PRI  Problem Solve, Improve Materials & Process, or Performance Low Priority, unless!  Production or cost impacted Issues

28. PRI Questions

29. PRI  Empty Empty