Forensics : Mix Conformance

Transcription

1 Forensics : Mix Conformance 2012 Rocky Mountain Asphalt Conference and Equipment Show Adam J.T. Hand, PhD, PE Granite Construction Incorporated February 23, 2012 Denver, CO

2 Forensics Fundamentally with problems we need to know: What is the performance issue? What was the cause(s)? How do we fix it or equitably pay for it? How do we prevent it in the future?

3 Have You Ever Been Involved in a Forensic Investigation?

4 Have You Ever Been Involved in a Forensic Investigation?

5 Have You Ever Been Involved in a Forensic Investigation? Which One We You? Designer Owner/Engineer Materials Supplier Contractor

6 Forensics Performance Problem or Distress Possible Inves,ga,on Requirements Records Review Field Distress Survey Structural Evalua,on Field Sampling and Tes,ng Lab Tes,ng Data Analysis Probable Cause(s) Repair/Rehabilita,on Alterna,ves Patch Sealing/ Micro- Milling Surface Level Surface Treat- Over- lay Remove and Replace Recon- struct

7 Ideal Forensic Team Pavement Performance/Analysis Expert Pavement Design/Structural Analysis Expert Soils/Aggregate Expert Asphalt Binder Expert HMA Materials Expert Plant Production Expert HMA Construction Expert Quality Control Expert

8 What Drives Performance? (HMA Mix Conformance Focus) Common HMA Distresses Permanent Deformation/Rutting/Corrugations/Bleeding Fatigue Cracking Thermal Cracking Durability Moisture Sensitivity Raveling Typical HMA Material Property Performance Trends

9 Failure Modes Load Related Permanent Deformation Fatigue Cracking Edge Cracking Non-Load Related Thermal Cracking Block Cracking Reflection Cracking Stripping Bleeding Raveling Potholes

10 Rutting

11 Locations and Mechanisms Shear Failure in HMA 9

12 Bleeding

13 Rutting Trends (Bleeding Also) Rutting Rutting Rutting %AC Design %AV Rutting Rutting Rutting Rutting In-Place %AV Time (Aging) Temperature %RAP

14 Rutting Trends (Bleeding Also) Rutting Rutting Rutting %Crushed Aggregate % Natural Sand Agg Surface Texture Rutting ARZ TRZ BRZ Gradation Type

15 Fatigue Cracking

16 Fatigue Trends Fatigue Life Fatigue Life Fatigue Life %AC Design %AV In-Place %AV Fatigue Life Time (Aging) Fatigue Life Temperature Fatigue Life %RAP

17 Fatigue Trends Fatigue Life Fatigue Life %Crushed Aggregate % Natural Sand Fatigeu Life Fatigue Life Agg Surface Texture ARZ TRZ BRZ Gradation Type

18 Thermal Cracking

19 Thermal Cracking Trends Thermal Cracking %AC Thermal Cracking Design %AV Thermal Cracking In-Place %AV Thermal Cracking Time (Aging) Thermal Cracking Temperature Thermal Cracking F/T Cycles

20 Thermal Cracking Trends Thermal Cracking %Crushed Aggregate Thermal Cracking % Natural Sand Thermal Cracking Agg Surface Texture Thermal Cracking ARZ TRZ BRZ Gradation Type 18

21 Moisture Sensitivity (Stripping)

22 Raveling

23 oisture Sensitivity Trends (Raveling Also) TSR TSR TSR TSR %AC Design %AV In-Place %AV TSR TSR Time (Aging) Temperature F/T Cycles

24 Compaction (In-Place Air Voids) & Performance Raveling Rut Depth Fatigue Life In-Place Air Voids (%) In-Place Air Voids (%) Cracking Moisture Damage In-Place Air Voids (%) In-Place Air Voids (%) In-Place Air Voids (%)

25 HMA Distress Types and Possible Causes

26 What Information is Needed? Pavement Distresses Drives Other Pavement Structural Design and As-Builts Geometric Design (w/ Drainage) Climatic Traffic/Loading Materials Soils, Aggregates Binder, Anti-Strip HMA Mix Design and Production PC/QC/QA Plant Production

27 Where Does the Data Come From? Design Records Production Records Construction Records Field Investigations Condition Survey FWD Trenching Coring Lab Testing INTERVIEWS

28 Interviews Who Saw What? Plant Plant Operator Plant Oiler Loader Operator Truck Drivers Paving Crew Foreman Paver Operator Screedman Laborer: Lutes can play a tune

29 Forensic Data Collection

30 Post-Failure HMA Challenges Representative Samples Age Raveling, Segregation RAP, RAS, RAP/RAS Test Methods Extraction, Recovery, Recovered Binder Properties, Modifiers Multiple Labs

31 Are You Still Awake?

32 Mix Conformance What Do We Have to Work With? Design vs. Production Materials and Quality Data Records: COC, BOL, Plant, QC/QA, and Tickets Is the Data Logical? Mix Design vs. Plant Records vs. Field Observations %AC+Gradation+Volumetrics+Stiffness/Stability Component and Blend Gradations (RAP and RAS) Design vs. Production Binder and Mix Stiffness

33 Paper Trail Binder and AntiStrip COC - Design BOL Production Mix Unique Product Codes Production Tonnages vs. BOL Production Tonnages vs. QC/QA

34 Plant Production Records Continuous Records Great JMF vs. Feed Tonnages (All, not just Bins) Moisture Discharge Temp Production (TPH) Loadout Silo Time, Tonnage, Ticketing

35 Consider Get Outside the Box Binder Chemical Analysis Binder-Design vs. Production vs. Pavement Anti-Strip Impact and where Added PPA Baghouse Fines Chemical Analysis CaO Ca(OH) 2 RAP and RAS

36 What is Logical and What Isn t? Putting the Pieces of the Puzzle Together

37 Make Your Life Easy - Everyday Prepare for Success Before Issues Control of Documents Control of Records Pictures Videos Correspondence Field Notebooks

38 Prepare For Success Before Issue Accredited Labs (AMRL, DOT) Certified Technicians (DOT, NICET) Engineer CEU s Design and PC/QC/QA Database Change-Auditable Know Your Specs and Job Notify Owner Retain Samples!!! Design and Construction

39 Paper Trail - Key Specification Submittal Mix Design Plant Production Controls Operations Ticketing QC/QA

40 ome More Memorable Forensics and ommon Themes (UNR, Purdue, Consulting) Raveling Stripping Near Rock Slippage Tender Mix Rutting Polymer Agglomerations Airfields Stains, Blisters, Bottled Water

41 Raveling/Stripping Neat PMB

42 Raveling/Stripping

43 Seal Coat Induced Stripping

44 Near Rock

45 Slippage

46 Rutting

47 Premature Cracking

48 Airfields Where Built? Stains Blisters Slippage Tining/FOD Tender Mix

49 Stains and Blisters

50 Tining and FOD

51 ommon Themes In-Place Density is Critical Amine Anti-Strip and PPA don t Mix Well! Prime and Tack Work! If it Doesn t Set Up, Put the Skippy to Work! Airfields are Built in the Wrong Location! 3/16 Masonry Bits Work! Boeing Doesn t Like FOD! There May Not Be a Silver Bullet!

52 One or More Weak Links Design Materials Construction Environment Climate

53 Root Cause Analysis Fundamental Understanding Fishbone Technique in RCA Not Finger-Pointing Not Cost-Sharing No Forgone Conclusions Just Plain Objective Evidence Structural Design Materials Construction Pavement Distress Geometric Design Climate Loading

54 Good Resources Good Examples TxDOT manual_notice.htm CalTrans mactec_caltrans_trb pdf or pubsindex.trb.org/view.aspx?id=749607

55 Wrapping Up Forensics are a Reality Understand Performance Drivers Use Rational Process of Discovery Listen to Ops Folks Be Objective Learn and Share Where Would You Start with Mix Conformance?

56 Thank You! Questions? Adam Hand Granite Construction Inc. (775)