Airport Pavement Distress: Types. Tom Freeman, P.E. Texas Transportation.

Transcription

1 Airport Pavement Distress: Types and dcauses Tom Freeman, P.E. Texas Transportation Institute Phone:

2 PMS Concepts

3 Pay me NOW!

4 Pay me LATER!

5 PMS Concepts 40 % Time $ % Time 90 % Time $3.50 $ 6.15 $14.00 AGE

6 Good Pavement Costs Less Than Bad Pavement

7 Good Pavement Costs Less Than Bad Pavement Over the long-term If and reasonable level of service is provided If the pavement will respond to preventive maintenance

8 Program Must Retain Good Pavement, While Repairing Poor Pavement

9 Pavement Management Based on finding a cost-effective treatment, At a given time, To give the desired level of service.

10 Inspection Procedures Inspect Primary Pavements FAA Condition Survey 20% Inspection Rate 2 Runways Taxiways Aprons Aprons Videotape Runway Ends and Representative Areas

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13 Inspection Procedures Inspect Primary Pavements FAA Condition Survey 20% Inspection Rate 2 Runways Taxiways Aprons Videotape Runway Ends and Representative Areas Document Conditions and Distresses With Digital Photos Plain English Report of Conditions Put all data on CD

14 Exam ple of a Runway Exam ple of a Runway Section Designation.

15 Step 1. Inspect sample units to determine type, quantity and severity level of pavement distresses. Low Severity Longitudinal Cracks Medium Severity Alligator Cracks Step 2. Determine deduct values. Density Density Step 3. Compute Total Deduct Value, TDV = a + b Step 4. Adjust Total Deduct Value Total Deduct Value Step 5. Compute Pavement Condition Index, PCI=100-CDV, for each sample unit inspected. Step 6. Determine Pavement Condition Rating Figure 2. PCI Calculation Procedure (2)

16 Performance of Center AC Pavements Basic General Transport Other ACCEN 2.75 Points/Yr PCI Family Curve for Center AC Pavements

17 Performance of Center AAC Pavements Basic General 80 Transport AACCEN 3.23 Points/Yr PCI Family Curve for Center AAC Pavements

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19 Edge Cracking and Encroachment

20 Edge Cracking and Encroachment Weathering and Raveling

21 Edge Cracking and Encroachment Weathering and Raveling Block Cracking

22 Edge Cracking and Encroachment Probably Low y Severity

23 Not Low Severity!

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25 Moisture Changes Along Edge of Pavement Less Water Under Pavement More Water Along Edge Soil Shrinks and Swells

26 Moisture Changes Along Edge of Pavement Less Water Under Pavement More Water Along Edge Soil Shrinks and Swells Differential Temperature Fix By Crack Sealing (Kill Weeds) May Be Able To Address In Design - Wider Bases

27 Weeds and Grasses Along Edge of Pavement Causes Cracking Along Edge, FOD, Weathering of Pavement Reduces Width of Pavement

28 Weeds and Grasses Along Edge of Pavement Causes Cracking Along Edge, FOD, Weathering of Pavement Reduces Width of Pavement Fix With Mowing, Herbicide, Grading, Millings, Wider Bases

29 Block Cracking - Low Severity

30 Medium Block Cracking, Medium Weathering

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32 Lack of Traffic Sun/Ultraviolet and Oxygen Remove Volatiles (Maltenes) Pavement Gets Brittle Daily and Annual Temperature Cycling

33 Lack of Traffic Sun/Ultraviolet and Oxygen Remove Volatiles (Maltenes) Pavement Gets Brittle Daily and Annual Temperature Cycling Asphalt Worn Away, Aggregate g Gets Loose Hello FOD, Goodbye Paint

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35 Fix Block By Mill and Overlay or Fix Block By Mill and Overlay or Reconstruct

36 Fix Block By Mill and Overlay or Reconstruct Expensive Deteriorates Slowly, So We Can Wait. Fog to Reduce Rate

37 Fix Block By Mill and Overlay or Reconstruct Expensive Deteriorates Slowly, So We Can Wait. Fog to Reduce Rate Fi W h i d R li b F Fix Weathering and Raveling by Fog, Rejuvenator, Slurry, Overlay, Reconstruct

38 When Is The Proper Time To Do Work?

39 Too Late?

40 Way Too Late!!

41 Wait Until Cracked and Slurry Seal

42 Cracks Come Right Back Through

43 Some Longitudinal and Transverse Cracking Fix by Sealing Cracks

44 Lots of Sealed Longitudinal Cracks

45 Crack Seal Under Slurry Seal Can Cause Problems

46 Routine Preventive Maintenance is the Key Preserve, Protect, or Renew Surface to Prevent Cracking For Airports, Block Cracking is Death. Must Treat BEFORE All Cracked Up!!

47 If We Wait Until It is All Cracked, Slurry Will Perform Poorly

48 If Cracks Are Small, Will Perform Better, But To PREVENT Reflection Cracking, Must Treat BEFORE It Cracks

49 Fog Seal (Use on HMAC, Slurry, Seal Coat) Dilute AC Emulsion Rejuvenators (HMAC Only) Specially Formulated To Replace Volatiles

50 Slurry Seal (Use on HMAC, Slurry, Seal Coat) Asphalt And Aggregate Crack Seal Do Same Things You Have Been Doing, Just Do Them Earlier

51 Fog Seal or Rejuvinator Pre-P401?

52 Slurry Seal

53 Seal Cracks (Every Two $0.10/Ft) Blade Edges and Kill Weeds (Annual) Fog Seal (Every 2-4 $ $0.20/SY) Rejuvenator (See Manufacturer) Slurry Seal (5-7 $1/SY)

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55 Lower Overall Cost Better Overall Condition i Fewer Complaints Less Down Time

56 PCI Good Fair Poor PCI Performance Curves for Microsurfacing i

57 Reconstruct PC CI 50 $12/SY $12/SY Total = $ Runway Closed 4-6 Months Each Time

58 Overlay $6/SY $6/SY $6/SY PC CI Total = $ Runway Closed 4-10 Days Each Time

59 100 Preventive 90 Maintenance PCI $1.50/SY $1.20/SY $1.50/SY Total = $ Runway Closed 1-3 Days Each Time

60 Where Do You Turn For TxDOT Assistance Division of Aviation Pilot Department of Transportation RAMP Coordinators Consultants Me - Tom Freeman T-Freeman@TAMU.EDU

61 Questions?

62 Tom Freeman, P.E. Texas Transportation Institute Phone: