Rigid Pavement Design - American Concrete Pavement Association

Rigid PavementFederal AviationAdministrationDesignPart ILarge CommercialAirportPresented to: ACPA-SE Concrete Airport PavementWorkshopBy: Jeffrey S Gagnon, P.E.Date: November 7, 2012

Starting Screen – No Job Files CreatedClick on “New Job”Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration2

Creating/Naming a Job FileEnter Job TitleClick OKRigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration3

Options ScreenClick OptionsRigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration4

Options ScreenRigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration5

Copy Basic Section/Pavement Typefrom SamplesClick on “Samples”Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration6

7 Basic Starting Structures in FAARFIELDSection Name Pavement TypeACAggregateAConFlexAConRigidNewFlexibleNew RigidPCConFlexPCConRigidNew flexible on aggregate baseHMA overlay on flexible pavementHMA overlay on rigid pavementNew flexible on stabilized baseNew rigid on stabilized basePCC Overlay on flexibleUnbonded PCC on rigidBe sure to select the pavement type that most correctly represents yourdesign requirements.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration7

Copy Basic Section/Pavement Typefrom SamplesDefault BasicPavement SectionsClick on “CopySection”Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration8

Copy a Sample Pavement SectionClick on desiredpavement section.Then click on theproject where thesection will besaved.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration9

Create a New Job TitleEnter job titleClick OKRigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration10

Create a New Job TitleClick “End Copy”Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration11

Working With a Pavement SectionSelect the job andthen the section youwant to analyze.Click on “Structure”to open the file.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration12

Working With a Pavement SectionThe selected samplepavement willappear.Click on “ModifyStructure” to modifythe structure ifdesired.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration13

New Rigid PavementDesign Example # 1• Pavement Structure:– PCC Slab, P-501, R = 700 psi– Cement-Treated Base, P-304, 6 in. thick– Crushed Aggregate Base, P-209, 8 in. thick– Subgrade k = 100 pci• Traffic Mix:– 10-Aircraft Mix includes B777, A340, A380Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration14

Modifying a Pavement SectionClick on the box forthe layer materialtype you want tomodify.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration15

Modifying a Pavement SectionSelect the layer typeyou want to includein the pavementsection.(P-304 for thisexample)Click OKRigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration16

Modifying a Pavement StructureChange P-209 layerthickness to 8 in.Change subgrade k to100 pciClick “End Modify”Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration17

Enter Traffic MixtureClick on “Airplane”to enter traffic mixRigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration19

Enter Traffic MixtureFor each airplane:Click on thedesired airplanegroup.Then select thedesired airplanefrom the library andclick “Add”Repeat for thecomplete trafficmixture.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration21

Traffic Mix for This ExampleNo. NameGross Wt.,lbs.AnnualDeparturesAnnualGrowth, %1 A320-100 150,796 600 0.002 A340-600 std 805,128 1,000 0.003 A340-600 std Belly 805,128 1,000 0.004 A380-800 1,239,000 300 0.005 B737-800 174,700 2,000 0.006 B747-400B Combi 877,001 400 0.007 B747-400 ER Pass. 913,000 300 0.008 B757-300 273,500 1,200 0.009 B767-400 ER 451,000 800 0.0010 B777-300 ER 777,000 1,000 0.0011 B787-8 (Preliminary) 486,000 600 0.00Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration22

Enter Traffic MixtureCertain airplanes mayappear in the list twice.This is to address thepresence of wing gearsand belly gears.FAARFIELD treatsthese as two airplanes.However, the weightand departures areinterlocked.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration23

Adjusting Airplane InformationGross Taxi Weight, Annual Departures and % Annual Growthmay be modified.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration24

Adjusting Airplane Information- Gross Weight• There are limitations on changes to airplane grossweights.• A range is provided for each airplane whichrepresents reasonable weights for the airplane:– Default Weight – 40%– Default Weight + 25%Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration25

Annual Departures in FAARFIELD• Annual departures has the same meaningas in the previous design procedure.• Arrivals are ignored.• For design purposes, FAARFIELD uses thetotal annual departures, multiplied by thedesign period in years:– e.g., 1200 annual departures × 20 years = 24,000departures.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration26

Adjusting Airplane Information- % Annual Growth of Annual Departures• Allowable range of percent annual growth is+/- 10%.• You can create the same effect by modifyingthe annual departures.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration27

Viewing Airplane InformationScroll over to revealadditional columnsof information.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration28

Viewing Airplane InformationAvailable in FAARFIELD Airplane Screen:Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration29

Viewing Airplane InformationValues in CDF andP/C ratio columnswill be zero whenairplanes are firstentered.Save the list whenfinished entering,then click the Backbutton.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration30

Run DesignClick on DesignStructureRigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration31

Run DesignDuring the designprocess, the “DesignRunning” clock willappear.For rigid designs, thedesign will normallytake a few minutes.Don’t interrupt theprocess.The screen displaywill change with eachiteration.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration32

Final Design – Example 1Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration33

Reviewing Airplane Data AfterCompleting the DesignClick on “Airplane”Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration34

Reviewing Airplane Data AfterCompleting the DesignCDF and P/C ratioinformation is nowavailable.This informationallows you to seewhich airplaneshave the largestimpact on thepavement design.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration35

CDF ContributionNo.NameCDFContributionCDF Maxfor AircraftP/CRatio1 A320-100 0.00 0.00 3.842 A340-600 std 0.24 0.24 1.913 A340-600 std Belly 0.00 0.14 2.474 A380-800 0.01 0.01 3.615 B737-800 0.00 0.01 3.526 B747-400 Combi 0.02 0.02 3.467 B747-400 ER Passenger 0.04 0.04 3.628 B757-300 0.00 0.00 3.959 B767-400 ER 0.06 0.07 3.6510 B777-300 ER 0.59 0.59 3.8611 B787-8 (Preliminary) 0.04 0.05 3.78Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration36

Saving and Reviewing the PavementDesign DataWhen finished withthe design, clickthe “Back” button.Click “Yes” to savethe data.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration37

Reviewing Design InformationTo view a summaryof the designinformation, clickthe “Notes” button.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration38

Reviewing Design InformationYou can view thesummary data orcopy it to otherelectronic media.Data can also beexported in XMLformat to allowautomated entryinto FAA Form5100.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration39

Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration40

Rigid Design – Stabilized BaseMaterial SensitivityP-306: PCC Surface - 18.27”P-304: PCC Surface – 18.38”P-401/403: PCC Surface – 18.40”18.5”Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration41

FAARFIELD Rigid Design - Sensitivity• Flexural Strength(w/ P-304 Base & K=100 pci)– 600 psi: 20.31”– 650 psi: 19.29– 700 psi: 18.38”– 750 psi: 17.49”• Subgrade K Value(w/ P-304 Base & 700 psi Flex)– 100 pci: 18.38”– 150 pci: 16.98”– 200 pci: 15.57”– 300 pci: 13.31”Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration42

Flexural Strength RequirementsAC 150/5320-6E “Airport Pavement Designand Evaluation” p. 34-35 Section 327.a“Although the flexural strength required for the pavement design is related to the flexural strength required by the P-501 specification, the strengths used for the pavement design and the P-501 specification are not necessarily thesame. Unless expedited construction requires early opening of the pavement to airplane traffic (e.g., less than 28days), Item P-501 typically uses a 28-day strength as a practical construction measure. However, the long-termstrength achieved by the concrete is normally expected to be at least 5 percent more than the strength measured at 28days.To establish the flexural strength for the thickness design the designer needs to consider several factors, such as:• Capability of the industry in a particular area to produce concrete at a particular strength• Flexural strength vs. cement content data from prior projects at the airport•T he need to avoid high cement contents, which can affect concrete durability• Whether early opening requirements necessitate using a lower strength than 28-dayThe FAA recommends a design flexural strength of 600 to 700 psi (4.14 to 4.83 MPa) for most airfield applications.Lower strength requirements allow balancing the components of the concrete mixture for performance but may resultin slightly thicker pavement requirements. However, these conditions reduce the risk of early cracking, minimizecurling and warping stresses, and provide increased performance with respect to fatigue. The strength used forthickness design should be reduced by 5 percent when stating the P-501 specification requirements for the 28-dayflexural strength.”Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration43

Flexural Strength RequirementsAC 150/5370-10F “Standards for SpecifyingConstruction of Airports”“501-3.1 PROPORTIONS. Concrete shall be designed to achieve a 28-day flexural strength that meets or exceeds theacceptance criteria contained in paragraph 501-5.2 for a flexural strength of [ ] psi. The mix shall be designedusing the procedures contained in Chapter 9 of the Portland Cement Association's manual, "Design and Control ofConcrete Mixtures".* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *The Engineer shall designate the design strength. Refer to AC 150/5320-6 for guidance when specifying flexuralstrength. The minimum flexural strength allowable for airport pavements is 600 psi (4 136 kPa).Higher flexural strength can be specified when local materials make this economically feasible. However, it must berecognized that due to variations in materials, operations, and testing, the average strength of concrete furnished by asupplier must be higher than the specified strength to insure a good statistical chance of meeting the acceptancecriteria throughout the duration of the job.For pavements designed to accommodate aircraft gross weights of 30,000 pounds (13 500 kg) or less, this sectionmay be modified to indicate that concrete shall be designed to achieve a 28-day compressive strength such that meetsor exceeds the acceptance criteria for a compressive strength of 4,400 psi (30 700 kPa).If the specified strength is required earlier than 28 days, the Engineer shall designate the time period.***********************************************************Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration44

Thank YouQuestions?Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration45

Rigid OverlayFederal AviationAdministrationDesignPart ILarge CommercialAirportPresented to: ACPA-SE Concrete Airport PavementWorkshopBy: Jeffrey S Gagnon, P.E.Date: November 7, 2012

FAARFIELD Overlay Design• HMA Overlays on Flexible Pavement– Same as designing a new flexible pavement, except the designlayer is the HMA overlay.• PCC Overlays on Flexible Pavement– Same principle as new rigid design.• HMA Overlays on Rigid Pavement• PCC Overlays on Rigid Pavement– More complex than new rigid pavement design.– Both slabs (base PCC and overlay) deteriorate with appliedtraffic. Stresses are computed for both slabs.– E-modulus of the base slab is a function of reduced SCI.– Subroutines were completely rewritten for FAARFIELD.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration47

FAARFIELD Overlay Design –PCC on Rigid Overlays• Fully bonded overlays– Treat as a new rigid pavement design.– Thickness of overlay slab is h overlay = h design – h exist .• Unbonded overlay– Bond breaker or leveling course is used.• Partially bonded overlay– No longer a standard design in AC 150/5320-6E.– Default in FAARFIELD is off.– May be enabled from the Options window, butdisplays a “Non Standard Structure” message.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration48

FAARFIELD Overlay DesignRequired Inputs• Existing rigid pavement condition is characterized by theStructural Condition Index (SCI).• SCI derived from PCI as determined by ASTM D 5340 AirportPavement Condition Index Surveys. The new AC givesguidance on SCI.• SCI is computed using only structural components from thePCI survey.• SCI = 80, FAA definition of structural failure (50% of slabs withstructural crack)• For existing pavements with structural damage (SCI < 100)– The user inputs a value of SCI for the existing pavement. The range ofallowable values depends on the overlay type:• Rigid on Rigid Overlays: SCI 40–100• Flexible on Rigid Overlays: SCI 67–100 (was 50-100)– The Help file gives approximate formulas for relating SCI to Cr and Cbfactors in earlier method.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration49

FAARFIELD – PCC Unbonded OverlayDesign Structural Condition Index (SCI)Rigid Pavement Distress Types Used to Calculate SCIDistressCorner BreakLongitudinal/Transverse/Diagonal CrackingShattered SlabShrinkage Cracks (cracking partial width of slab)*Spalling–JointSpalling–CornerSeverity LevelLow, Medium, HighLow, Medium, HighLow, Medium, HighLowLow, Medium, HighLow, Medium, High* Used only to describe a load-induced crack that extends only part of the way acrossa slab. The SCI does not include conventional shrinkage cracks due to curing orother non load-related problems.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration50

Cumulative Damage Factor Used (CDFU)• For existing pavements where SCI=100(no structural distress):– There is no visible distress contributing to reductionin SCI (no structural distress types). However, somepavement life has been consumed by the appliedtraffic.– The amount of pavement life consumed is thepercent CDF Used (%CDFU).– Need to estimate a value of %CDFU.– The Help file gives guidance on estimating %CDFUusing the Life key.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration51

Cumulative Damage Factor Used (CDFU)– CDFU defines the amount of structural life used.• For structures with aggregate base:• L U = number of years of operation of the existing pavement until overlay• L D = design life of the existing pavement in years– FAARFIELD modifies this relationship for stabilizedsubbases to reflect improved performance.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration52

Rigid on Rigid Overlay SCIExample• Pavement Structure:– Rigid Overlay (P-501)– PCC Slab (P-501), 17.5 in.,R = 700 psi, SCI = 70– Cement Treated Base (P-304), 6 in.– Crushed Aggregate Base (P-209), 8 in.– Subgrade k = 100 pci• Traffic Mix:– Add A380-800 and B-747-8 Freighter to Aircraft listRigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration53

Rigid Overlay DesignClick “Back”Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration54

Rigid Overlay DesignRigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration55

Rigid Overlay Design - Copy Basic SectionClick on “Samples”Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration56

Rigid Overlay Design - Copy Basic SectionDefault BasicPavement SectionsClick on “CopySection”Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration57

7 Basic Starting Structures in FAARFIELDSection Name Pavement TypeACAggregateAConFlexAConRigidNewFlexibleNew RigidPCConFlexPCConRigidNew flexible on aggregate baseHMA overlay on flexible pavementHMA overlay on rigid pavementNew flexible on stabilized baseNew rigid on stabilized basePCC Overlay on flexibleUnbonded PCC on rigidBe sure to select the pavement type that most correctly represents yourdesign requirements.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration58

Rigid Overlay Design / Copy a SamplePavement SectionClick on desiredpavement section.Then click on theproject where thesection will besaved.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration59

Rigid Overlay Design / Create a NewJob TitleEnter job titleClick OKRigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration60

Rigid Overlay Design / Create a NewJob TitleClick “End Copy”Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration61

Rigid Overlay Design / Working Witha Pavement SectionSelect the job andthen the section youwant to analyze.Click on “Structure”to open the file.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration62

Rigid Overlay DesignStandard Cross SectionClick on “ModifyStructure”.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration63

Rigid Overlay DesignModify the CrossSectionClick on “Airplane”.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration64

Rigid Overlay Design - Add AirplaneFor each airplane:Click on thedesired airplanegroup.Then select thedesired airplanefrom the library andclick “Add”Click “Save”Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration65

Performing Overlay DesignThe layer with thesmall arrow is thelayer that will beadjusted to providethe structuraldesign.The location of thearrow isdetermined by thetype of structure.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration66

Performing Overlay DesignYou are now readyto design thestructure. Simplyclick on “DesignStructure.”The program willkeep you informedabout the status ofthe design.Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration67

Result of Overlay Design10.5”P-501 PCC OverlayRigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration68

Rigid on Rigid Overlay % CDFUExample• Pavement Structure:– Rigid Overlay (P-401)– PCC Slab (P-501), 16.0 in.,R = 700 psi, SCI = 100– Cement Treated Base (P-304), 6 in.– Crushed Aggregate Base (P-209), 8 in.– Subgrade k = 100 pci• Traffic Mix:– Original B737-800, B737- 900 and A310-300– Add B-747-400ER, B767-300ER and B777 (all FreighterModels)Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration69

Calculation of %CDFUChange Designlife from 20 to 8Click LifeRigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration70

% CDFU Calculated%CDFU= 50%Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration71

Make Sure tomodify allrelevant dataRigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration72

You are now readyto design thestructure. Simplyclick on “DesignStructure.”Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration73

Result of Overlay Design7.5”P-501 PCC OverlayRigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration74

Software Available at:• http://www.faa.gov/airports/engineering/design_software/• http://www.airporttech.tc.faa.gov/naptf/download/index1.aspRigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration75

Thank YouQuestions?Rigid Pavement Design – Part INovember 7, 2012Federal AviationAdministration76