Rigid Pavement Design Deficiencies
• Major shortcomings of JPCP designs based on 1972-1986 versions of the AASHTO Guide :– inadequate joint load transfer, – long joint spacing, – erosion of base/subbase, – poor subdrainage– etc.
• Deterioration occurs early• Rehabilitation needed
Development of Supplemental AASHTO Design Procedure for
JPCP
• Serious deficiencies noted in 1986 AASHTO procedure
• Studies showed major flaws in base/subgrade support procedures
• No easy fixes• Improved structural (3D finite
element) model for JPCP was developed to correct deficiencies
Development, Validation, Adoption:
1998 Supplemental Rigid Pavement Design Procedure
• Developed under NCHRP Project 1-30 (University of Illinois at Urbana-Champaign)
• Validated under FHWA/LTPP research study (ERES Consultants/ARA) • Adopted by AASHTO as Supplementary Rigid Pavement Design
Procedure (1998)• FHWA/LTPP - Supplementary Rigid Pavement Design
Spreadsheet (ERES Consultants/ARA)
Only JPCP For Now
Jointed plain Jointed plain concrete pavementconcrete pavement
(JPCP)(JPCP)
• Most constructed rigidMost constructed rigidpavementpavement
• Basic design procedure Basic design procedure developeddeveloped
• Procedure field verifiedProcedure field verified
Jointed reinforcedJointed reinforcedconcrete pavementconcrete pavement
(JRCP)(JRCP)Continuously reinforcedContinuously reinforced
concrete pavementconcrete pavement(CRCP)(CRCP)
• Limited field verificationLimited field verification
1998 AASHTO JPCP Design Is Better
• Improved structural modeling• Improved subgrade characterization• Base course as structural layer• Transverse joint spacing• Climate at site is considered directly• Shoulder type and slab width• Joint faulting and cracking checks
Use of LTPP Data to Verify1998 AASHTO Design
• Design procedure verified using field data from LTPP
• Inputs to 1998 AASHTO design model obtained
• Actual traffic log ESALs compared to predicted log W (ESALs)
• No significant bias found in predicting serviceability of pavements in four climatic zones
PRESENTATION OBJECTIVES
• What is the Rigid Pavement Design (RPD) Software?
• Development of RPD Software• RPD Software Features and
Capabilities • How To Use The RPD Software • Who Should Use the RPD Software and Why• How to Get the RPD Software
Rigid Pavement Design Spreadsheet: Features
I. Input Sheet - General Information
The general information section requests information about the agency. This information is not required for the analysis, but the information entered here may be displayed on the "Results" sheet.
II. Input Sheet - Design Information
All design inputs are required except sensitivity analysis.No default values are used.
Information can be retrieved from the "Saved Data" sheet using the "Retrieve Data"button. The existing data can be replaced or saved as a new set using the"Save Data" button. Clicking on the "Retrieve Data" button opens the "Saved Data" sheet. Select theappropriate row to be retrieved and click on the "Export" button.If the retrieval is successful, the data are retreived. Changes can be made and savedas a new data set using a different value for the search ID. The data can also
Information sheet containing spreadsheet “User Guide”
Rigid Pavement Design Spreadsheet: Features
Command buttons for easy navigation between sheets
Rigid Pavement Design Spreadsheet: Features
Command button links to reference tables
Joint spacing and edge support conditions are direct inputs
Rigid Pavement Design Spreadsheet: Features
Climatic properties are direct inputs in the supplemental rigid pavement design
Rigid Pavement Design Spreadsheet: Features
True subgrade k-value is used (not adjusted for top-of-base)
Rigid Pavement Design Spreadsheet: Features
Easy links to sensitivity analysis for various design inputs
Rigid Pavement Design Spreadsheet: Features
Project data can be saved in rows and exported to the main sheets
Rigid Pavement Design Spreadsheet: Features
Sensitivity Analysis plot displays inputs held constant
Rigid Pavement Design Spreadsheet: Features
Results
Project #1-20-98LCBDescription: Lean Concrete Base, 5-in.
Location: Champaign, IL
Slab Thickness Design
Pavement Type JPCP18-kip ESALs Over Initial Performance Period (million) 21.88 millionInitial Serviceability 4.5Terminal Serviceability 2.528-day Mean PCC Modulus of Rupture 700 psiElastic Modulus of Slab 4,500,000 psiElastic Modulus of Base 25,000 psiBase Thickness 6.0 in.
Results sheet can be viewed on screen or can be printed
Rigid Pavement Design Spreadsheet: Features
D Design Traffic L E l F(in) MESALs in in
7.0 1.32 180 1.00 29.88 1.10
7.5 1.92 180 1.00 31.47 1.10
8.0 2.76 180 1.00 33.03 1.09
8.5 3.92 180 1.00 34.57 1.08
9.0 5.51 180 1.00 36.08 1.08
9.5 7.65 180 1.00 37.58 1.07
10.0 10.50 180 1.00 39.05 1.07
10.5 14.25 180 1.00 40.50 1.06
11.0 19.11 180 1.00 41.94 1.05
11.5 25.35 180 1.00 43.36 1.05
12.0 33.29 180 1.00 44.77 1.04
12.5 43.30 180 1.00 46.16 1.03
13.0 55.83 180 1.00 47.54 1.03
13.5 71.37 180 1.00 48.91 1.02
14.0 90.51 180 1.00 50.26 1.02
14.5 113.94 180 1.00 51.60 1.01
15.0 142.42 180 1.00 52.93 1.00
11.00 19.11 180 1.00 41.94 1.05
11.24 21.91 180 1.00 42.63 1.05
Calculation sheet shows all calculations and displays design traffic for different slab thicknesses
Rigid Pavement Design Spreadsheet: Features
Faulting Check sheet used to estimate faulting over design life for doweled and nondoweled pavements
PRESENTATION OBJECTIVES
• What is the Rigid Pavement Design (RPD) Software?
• Development of the RPD Software• RPD Software Features and Capabilities • How To Use The RPD Software • Who Should Use the RPD Software and
Why• How to Get the RPD Software
Systems Requirements
• IBM PC running:Microsoft Office 95 or 97 or
Microsoft Excel 7.0
Using The RPD Software
• Copy the Rigid Pavement Design (RPD) Software spreadsheet to the hard drive
• The RPD software cannot be run from the floppy drive
• Open the RPD spreadsheet using Microsoft Excel
Using The RPD Software
Click on Enable Macros to allow execution of spreadsheet macros
Using The RPD SoftwareClick on Input Form to access the main sheet
Using The RPD SoftwareEnter General Information for the project as shown below:
Using The RPD Software
Scroll down to enter Serviceability and PCC Properties
Using The RPD Software
Enter Base Properties, Reliability, and Standard Deviation
Click on Table 14 for friction factors for different base types
Using The RPD SoftwareClick on Input Form to navigate back to the main screen
Using The RPD Software
Select Pavement Type and Edge Support Condition
Enter Joint Spacing
Using The RPD SoftwareEnter Climatic Properties for the design region. Click on Table 15 for climatic properties for major metropolitan areas in each State.
For the first run enter the approximate subgrade k-value
Using The RPD Software
Click on Calculate Traffic for traffic calculation worksheet
Using The RPD SoftwareAfter entering traffic design inputs click Calculate
Click Export to Input Form
Using The RPD SoftwareClick on Calculate on the main sheet to calculate thickness for design inputs
Click on Calculate Seasonal k-Value for calculating seasonally adjusted k-value
Using The RPD Software
Enter number of months and subgrade k-value for each season. Click Calculate.
Using The RPD SoftwareUse the chart to estimate adjusted k-value for fill layer above the subgrade and/or rigid layer beneath the subgrade
Using The RPD SoftwareClick on Calculate on the main sheet to recalculate thickness for design inputs with the adjusted k-value
Using The RPD Software
Enter thickness for sensitivity analysis
Click Slab Thickness Sensitivity for sensitivity analysis of design traffic to slab thickness
Click on radial buttons for sensitivity analysis of design traffic to different design inputs
Using The RPD Software
Using The RPD Software
Using The RPD SoftwareClick on Faulting Check to perform checks for doweled and nondoweled faulting
Using The RPD Software
Enter dowel diameter and other design inputs for doweled pavements
Using The RPD SoftwareClick on FI Table or Drainage Coeff. Table for tables containing information regarding these inputs
Click Calculate to obtain estimated faulting at end of design life
Click Results to view and print results
Using The RPD Software
Enter design inputs for nondoweled faulting check and click Calculate
Click Corner Break Check to perform top-down cracking analysis
Using The RPD Software
The critical values for joint faulting can be changed by entering the appropriate values below
Using The RPD Software
On the Corner Break Check worksheet enter the built-in temperature gradient related to construction curling and moisture gradient
Using The RPD SoftwareUse one of six charts provided to estimate tensile stress at top of slab from total effective negative temperature differential
Using The RPD SoftwareThe tensile stress at the top of the slab is less than the bottom up tensile stress for which the pavement is designed
Using The RPD SoftwareResults sheet can be viewed on screen or can be printed
Click Save Data to save the design information entered
Using The RPD Software
Enter ID for saving data and click OK
Using The RPD Software
All design information is saved in rows with the first column corresponding to the data set ID
Select appropriate row and click Export to export design information from this sheet to main sheet. This sheet can be accessed by clicking on Retrieve Data on the main sheet.
PRESENTATION OBJECTIVES
• What is the Rigid Pavement Design (RPD) Software?
• Development of the RPD Software• RPD Software Features and Capabilities • How To Use The RPD Software • Who Should Use the RPD Software &
Why• How to Get the RPD Software
Users of the RPD Software
• State and Provincial Highway Engineers
• Consulting Engineers
Benefits of Rigid Pavement Design
Software• Provides key answers not previously
addressed:– How do I adequately characterize the
subgrade support?– What is the best base type for the
conditions?– What is the optimum joint spacing?– Will this pavement fault or have corner
breaks?
PRESENTATION OBJECTIVES
• What is the Rigid Pavement Design (RPD) Software?
• Development of the RPD Software• RPD Software Features and Capabilities • How To Use The RPD Software • Who Should Use the RPD Software &
Why• How to Get the RPD Software
Get & Use The Software
• Order software:
-- Through LTPP homepage
www.tfhrc.gov
-- Through LTPP customer
service
Call 865-481-2967
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