# Presentation: 258709

## Update - Gyratory Design of Hot Mix Asphalt for Airfield Pavement

- Eastern Region Airports Conference

- Rodney Joel, P.E.

- March 18, 2008

## HMA DESIGN USING GYRATORY COMPACTOR

**The Federal Aviation Administration recognizes that the industry trend in the United States is to design Hot Mix Asphalt (HMA) using gyratory compaction equipment.**
**Industry is following direction provided by the Federal Highway Administration and the Strategic Highway Research Program (SHRP)**

## HMA DESIGN USING GYRATORY COMPACTOR

**Since 1987 the SHRP has promoted the use of gyratory design for HMA (known as SUPERPAVE)**
**Currently most US states use SUPERPAVE design procedures for highway applications**
**Since the highway paving industry is much larger than the aviation paving industry, laboratories and personnel have switched focus and knowledge to gyratory design.**

## HMA DESIGN USING GYRATORY COMPACTOR

**Traditional P-401 asphalt material has performed satisfactory.**
**Material requirements of P-401 similar to SUPERPAVE**
**Our challenge is how to produce a similar HMA product using gyratory equipment****	**
- Appropriate N-design values (number of gyrations for design)
- Appropriate PG grade asphalt requirements
- Aggregate gradation requirements?

## HMA DESIGN USING GYRATORY COMPACTOR

**FAA INTERIM GUIDANCE**
**Engineering Brief #59A****	****Item P 401 Plant Mix Bituminous Pavements (Superpave)**
**MAY 2006, (original Dec. 2001)**
**Provides Guidance and specification for basic gyratory mix design**
**Requires a Modification to Standards**

## HMA DESIGN USING GYRATORY COMPACTOR

_**Engineering Brief #59A**_
**Follows general SUPERPAVE requirements**
**Material requirements similar to existing P-401**
**P-401 acceptance criteria built into EB59A**
**Version “A” – allows use on all airport pavements**

## HMA DESIGN USING GYRATORY COMPACTOR

_**Engineering Brief #59A – Gradation Requirements**_

- Basic P-401 Gradation Band

## HMA DESIGN USING GYRATORY COMPACTOR

_**Engineering Brief #59A – Gradation Requirements**_
-  Layer thickness requirements
**EB59A **
-      3 times “nominal max”        e.g.  1/2” agg. => Min lift thickness = 1-1/2”
**P-401**
-      2 times “max”
- 		Similar to EB59 since max agg is one sieve larger than           nominal max **      **

## HMA DESIGN USING GYRATORY COMPACTOR

_**Engineering Brief #59A – Binder Requirements**_
**Uses PG grading system****     (current P-401 now uses PG system)**
**Initial selection based on climate**
**Bump requirement based on aircraft gross weight**

## HMA DESIGN USING GYRATORY COMPACTOR

_**Engineering Brief #59A – Binder Requirements**_

- Note to Engineer -- Specification of Performance Graded asphalt should be _consistent with the recommendations of the applicable State Department of Transportation and be locally available_.  In the absence of guidance from a state DOT, the recommendations from the Long Term Pavement Performance Binder Software, LTPPBind.exe should be used in conjunction with Table A.  In general, _a high reliability (98 percent) on both the high and low temperature categories is sufficiently conservative_.  Grade bumping of performance graded binders is permitted, and interim guidance is provided in Table A until ongoing research under the AAPTP program is completed.

## HMA DESIGN USING GYRATORY COMPACTOR

_**Engineering Brief #59A – Binder Bumping Requirements**_

## HMA DESIGN USING GYRATORY COMPACTOR

_**Engineering Brief #59A – Mix Design Requirements**_

- Under 60,000 lbs                   Over 60,000 lbs

## HMA DESIGN USING GYRATORY COMPACTOR

_**Engineering Brief #59A – Acceptance Criteria**_
**Plant produced material**
- Air Voids
**Field placed material**
- Mat Density
- Joint Density
- Thickness
- Grade
- Smoothness

## HMA DESIGN USING GYRATORY COMPACTOR

_**Engineering Brief #59A – Acceptance Criteria**_
- Air Voids
- 90 PWL
- 	Target production 3.35% - 4.65%
- 	STD – 0.65

## HMA DESIGN USING GYRATORY COMPACTOR

_**Engineering Brief #59A – Acceptance Criteria**_
- Mat Density
- 90 PWL
- 	Target production 94.5% (max theo)
- 	STD – 1.3

## HMA DESIGN USING GYRATORY COMPACTOR

_**Engineering Brief #59A – Acceptance Criteria**_
- Joint Density
- 90 PWL
- 	Target production 92.8% (max theo)
- 	STD – 1.8

## HMA DESIGN USING GYRATORY COMPACTOR

_**Engineering Brief #59A – Acceptance Criteria**_

- Optional Table 5 (2 sided density)

## HMA DESIGN USING GYRATORY COMPACTOR

_**Engineering Brief #59A – Payment (single sided density)**_

## HMA DESIGN USING GYRATORY COMPACTOR

_**Engineering Brief #59A – Payment (2-sided density)**_

## HMA DESIGN USING GYRATORY COMPACTOR

**HMA DESIGN USING ****GYRATORY COMPACTOR**

_**Engineering Brief #59A – Payment**_

- Production must stay focused on desired density to achieve full pay
- No encouragement to go over desired range

## HMA DESIGN USING GYRATORY COMPACTOR

_**Engineering Brief #59A – Payment (2-sided density)**_

## HMA DESIGN USING GYRATORY COMPACTOR

**Three areas of active research**
**FAA Technical Center, Atlantic City, NJ**
- Interagency Agreement with the US Army Corp of Engineers (ERDC), Vicksburg, Mississippi
- Support Contract work with SRA International, Inc
**Asphalt Airfield Pavement Technology Program (AAPTP)  Projects 04-2 and 04-3**

## HMA DESIGN USING GYRATORY COMPACTOR

**ERDC, Vicksburg, MS (Interagency Agreement)**
- Factors considered
- One asphalt grade (PG64-22)
- Aggregate geology,
- Aggregate quality (crushed/natural sand),
- Maximum size / Grain size distribution
- Completed testing on 36 mix designs (Marshall & Gyratory)
- Most of the mixes not compliant with P401 specification
- Performed limited analysis (air void versus gyrations)
- Found variation with aggregate types

## HMA DESIGN USING GYRATORY COMPACTOR

- ERDC, Vicksburg, MS (Interagency Agreement)
- Work to continue in 2008
- Using mixes known to meet P-401
- Volumetric properties only
- Include modified binders

## HMA DESIGN USING GYRATORY COMPACTOR

- SRA International, Inc. (FAA support contractor)
- Subcontracts awarded to –
- Advanced Asphalt Technology
- Soiltek
- Will test “Well Performing Mixes”

## HMA DESIGN USING GYRATORY COMPACTOR

- SRA International, Inc. (FAA support contractor)
- Testing will include
- Volumetrics
- Air voids, VMA, Flow, Stability
- Performance Parameters
- Repeated load confined creep test
- Dynamic modulus
- APA rut test
- Results anticipated Late 2008

## TESTING PROGRAM TO SUPPORT ESTABLISHMENT OF SUPERPAVE COMPACTION REQUIREMENTS FOR THE FEDERAL AVIATION ADMINISTRATION HOT MIX ASPHALT SPECIFICATION

**Don Christensen, P.E., Ph.D.**
**Advanced Asphalt Technologies, LLC**
**dwcaat@aol.com**
**Thomas Bennert**
**Rutgers University**
**bennert@eden.rutgers.edu**
**Roy D. McQueen, P.E. **
**Roy D. McQueen & Associates, Ltd.**
**rdmcqueen@rdmcqueen.com**

**Slides Courtesy of Roy McQueen and Associates**

## Acknowledgements

- Project funded by Federal Aviation Administration                                        contact: Navneet Garg, PhD
- Project administered by SRA, Inc   contact: Harkanwal Brar, PhD

## Objective of Study

- Recommend Ndesign for the gyratory compactor using Marshall mix design proportions for FAA P-401
- Performance equivalent to Marshall mix designs
- Verification testing on a variety of mixes

## Stated Differently

**Make sure the new stuff works as good as the old!**

## Average PCI at Civil Airports

**Source: Report DOT/FAA/AR-04-46**

## General Approach

- Test Plan
- Phase I Testing
- Phase II Testing
- Final Report

## Overview of FAA P-401

- 75 blow Marshall for heavy duty
- Design VTM: 2.8% - 4.2%, 3.5% typical
- VMA typically 1% higher than MS-2
- TSR for moisture susceptibility (75%-80% min)
- Compaction function of lab Marshall density
- PWL acceptance:
- Density: 90% above 96.3%      98% average
- Air voids: 90% between 2% and 5%

## Density Limit Derivation

- 10 PD

- 90 PWL

- L

- 98%

**L = 98% - 1.28(1.3%) = 96.3%**

- Zs

## Air Voids Design Limits

- L=2%

- U=5%

- 3.5%

**D****L****= 2% + (1.28x0.65%) = 2.8%**

**D****U****= 5% - (1.28x0.65%) = 4.2%**

- Zs

- Zs

- 2.8%

- 4.2%

- 0.7%

- 0.7%

## Differences Between P-401 Marshall and P-401 Superpave

**P-401Marshall       (AC 150/5370-10C)**
- Avg. 98% lab density
- Avg. 3.5% VTM
- 1% higher VMA

**P-401 Superpave  (EB 59A)**
- Avg. 94.5% MTD
- Avg. 4% VTM
- 1% lower VTM

## Overview of Phase 1 and 2

- Phase 1:
- Determine N-equiv
- Equivalent to 75-blow Marshall
- Phase 2:
- Validate N-equiv
- Performance Tests for N-equiv

## Phase 1 Subtasks

- Identify Mixtures and Binders
- Verify Mix Designs
- Perform 1st and 2nd  Replicates of Gyratory Compaction & Volumetrics
- Perform Mixture Variation Experiment
- Compile, Analyze and Summarize Data

## Mix Variables (1)

- Well-performing mixes
- Various mineralogy
- Gneiss
- Dolomite
- Granite
- Gravel
- Basalt
- Argillite
- Diabase

## Mix Variables (2)

- Nominal Maximum Aggregate Size
- 12.5 mm
- 19.0 mm
- 25.0 mm
- Natural sand content

## Identified Well-performing Mixes

| Mix Name | Airport | Aggregate Type | Nominal Maximum Aggregate Size | Original Binder Grade |
| --- | --- | --- | --- | --- |
| JFK/1993 | JKF | Gneiss | 12.5 mm | AC 20 |
| JFK/1997 | JFK | Dolomite | 19 mm | PG 82-22 |
| JFK/1996 | JFK | Dolomite/granite | 25 mm | PG 82-22 |
| Atlantic City | ACY | Basalt | 19 mm | PG 64-22 |
| Lexington | LEX | Limestone | 19 mm | PG 70-22 |
| Elmira | ELM | Crushed gravel | 19 mm | PG 64-28 |
| NAPTF | --- | Argillite | 12.5 mm | PG 64-22 |
| Charlottesville | CHO | Diabase | 19 mm | PG 64-22 |

## Verify Mix Designs

- Sample, Prepare and Compact
- Volumetric Analysis
- % AC
- VTM
- VMA
- Replicate voids within 0.5%
- Vary %AC, if necessary

## Gyratory Compaction & Volumetric Analysis

- Prepare mixes at 50, 75, 100 & other gyrations
- Regression analysis for each mix to obtain same air voids as Marshall
- Replicate testing

## Mixture Variation Experiment 

**Mixture Variation Experiment**

- Vary binder type
- PG 64-22
- PG 76-22 (elastomeric)
- PG 76-22 (plastomeric)
- Vary natural sand content
- 0%
- 7.5%
- 15%

## Binder Variations

| Mix Name | Binder Grade |  |  |
| --- | --- | --- | --- |
|  | PG 64-22 | PG 76-22
 SBS-modified | PG 76-22
PE-modified |
| JFK/1993 | X | X | X |
| JFK/1997 | X | X | X |
| JFK/1996 | X | X | X |
| Atlantic City | X |  |  |
| Lexington | X |  |  |
| Elmira | X | X | X |
| NAPTF | X |  |  |
| Charlottesville | X | X | X |

## Compile, Analyze & Summarize Data

**Compile, Analyze & Summarize Data**

- Analysis of variance
- N-equiv through regression analysis
- Target air voids = 3.5%
- Air voids deviations

## Phase 2 Tasks

- Verify Selected Gyratory Mix Designs
- Performance Tests
- Fatigue Resistance
- Rut Resistance)
- Moisture Susceptibility

## Why Phase 2?

- Because one size probably will not fit all
- i.e., A probable range in N-equiv will result

## Verify Selected SQC Mix Designs

- 8 to 12 selected mixes
- Adjust %AC to reach target air voids for Phase 1 N-equiv
- Compare to Phase 1

## Phase 2 Performance Tests

- Evaluate Fatigue Resistance Using Uniaxial Testing
- Evaluate Rut Resistance Using Simple Performance Test (SPT)
- Evaluate Rut Resistance Using Asphalt Pavement Analyzer (APA)
- Evaluate Moisture Susceptibility Using TSR

## HMA DESIGN USING GYRATORY COMPACTOR

- AAPTP Research Projects
- 04-2, PG Binder Selection for Airfield Pavements
- Awarded to Advanced Asphalt Technologies
- Scheduled completion Oct., 2007 (extended)
- 04-3, Implementation of Superpave Mix Design for Airfield Pavements
- Awarded to Burns, Cooley, Dennis, INC
- Scheduled completion Feb., 2008 (extended)

## HMA DESIGN USING GYRATORY COMPACTOR

- AAPTP Research Projects (www.aaptp.us)

## HMA DESIGN USING GYRATORY COMPACTOR

- 04-2, PG Binder Selection for Airfield Pavements
- Binder selection criteria
- Following LTPPBind for initial grade selection
- Mostly controlled by climate
- 98% reliability
- Grade bumping criteria
- Usage based grade bump criteria
- parking, taxiway, or runway
- Larger bumps for static traffic

## HMA DESIGN USING GYRATORY COMPACTOR

- 04-2, PG Binder Selection for Airfield Pavements
- Factors that must be considered
- tire pressure,
- Tire size,
- aircraft speed,
- traffic level,
- aircraft wander
- depth within the pavement

## HMA DESIGN USING GYRATORY COMPACTOR

- 04-3, Implementation of Superpave Mix Design for Airfield Pavements
- Selected several existing airport pavements for evaluation (standard P-401 material)
- Obtain aggregate and binder materials to match project
- Reproduce mixture at 50 and 75 blow Marshalland 35, 50, 75, and 100 gyrations

## HMA DESIGN USING GYRATORY COMPACTOR

- 04-3, Implementation of Superpave Mix Design for Airfield Pavements
- Performance testing
- Repeated Load Confined Creep Test
- Triaxial test, 40 psi confinement
- 0.1 second load, 0.9 second rest period
- Deviator loads, 100, 200, and 350 psi
- Represents 	< 60,000 lbs and tire pressure < 100 psi			> 60,000 lbs and tire pressure > 100 psi		Tire pressures over 200 psi

## HMA DESIGN USING GYRATORY COMPACTOR

- 04-3, Implementation of Superpave Mix Design for Airfield Pavements
- Volumetric properties complete
- Performance testing
- Physical testing starts in September, 2007
- Anticipate results by February, 2008

## Questions or Comments?

## NEW  TOPIC

- ACN / PCN

## FAA Guidance on ACN-PCN

***FAA Guidance on ACN-PCN***

- AC 150/5335-5A
- STANDARDIZED METHOD OF REPORTING AIRPORT PAVEMENT STRENGTH – PCN
- Revised September, 2006
- 2005 - PCN field re-activated in 5010 Database

## ACN/PCN Definitions

***ACN/PCN Definitions***

- ACN
- 	“A number expressing the _relative effect_ of an aircraft on a pavement for a specified standard subgrade strength.”
- PCN
- 	“A number expressing the bearing strength of a pavement for _unrestricted_ operations.”
- Aerodrome Design Manual, Part 3 Pavements, Chapter 1

## 	A pavement with a given PCN can support without weight restriction, an airplane with an ACN rating equal to or less than the pavement PCN value.

- 	A pavement with a given PCN can support without weight restriction, an airplane with an ACN rating equal to or less than the pavement PCN value.

***ACN/PCN System - Concept***

## Why not continue reporting allowable “Gear” load?

Pavement thickness design requires not only the load magnitude but also the frequency of application. Therefore if an allowable gear load is reported, some knowledge about the frequency of load application is necessary for proper implementation.
For airport pavement applications we use the term “annual departures” to discuss frequency

- Why not continue reporting allowable “Gear” load?
- Pavement thickness design requires not only the load magnitude but also the frequency of application. Therefore if an allowable gear load is reported, some knowledge about the frequency of load application is necessary for proper implementation.
- For airport pavement applications we use the term “annual departures” to discuss frequency

***ACN/PCN System***

## 2D landing gear – fixed wheel spacing
Weights 300k, 400k, & 500k

- 2D landing gear – fixed wheel spacing
- Weights 300k, 400k, & 500k

***ACN/PCN System ***

- Increasing Frequency

- Increasing Thickness

- 2 Duals in
- Tandem
**2D**

- 300k

- 500k

- 400k

## Weight held at 200,000 lbs

Gear Type is
Very Important

- Weight held at 200,000 lbs
- Gear Type is
- Very Important

***ACN/PCN System ***

- Increasing Frequency

- D

- 2D

- Increasing Thickness

## 2D landing gears 
Constant gross load of 200,000 lbs

Same gear type but with differentwheel spacing

- 2D landing gears
- Constant gross load of 200,000 lbs
- _Same gear type_ but with differentwheel spacing

***ACN/PCN System ***

- Increasing Frequency

- Increasing Thickness

- Which 200k, 2D gear did you use to generate an allowable gear load?

## ACN – PCN procedure standardizes the frequency issue by making calculations of ACN/PCN at 10,000 coverages

(Due to airplane wander, It takes more than one pass of an airplane to equal a full coverage) 

- ACN – PCN procedure standardizes the frequency issue by making calculations of ACN/PCN at 10,000 coverages
- (Due to airplane wander, It takes more than one pass of an airplane to equal a full coverage)

***ACN/PCN System - Concept***

## ACN-PCN Application

***ACN-PCN Application***

- Applies only to pavements with bearing strengths of 12,500 pounds (5,700 kg) or greater.
- The method of reporting pavement bearing strength for pavements of less than 12,500 pounds (5,700 kg) remains unchanged.

## Only intended as a method for airport operators to evaluate acceptable operations of airplanes

It provides a load, or damage rating relative to a specified reference load.

ACN is not a pavement design procedure.

- Only intended as a method for airport operators to evaluate acceptable operations of airplanes
- It provides a load, or damage rating relative to a specified reference load.
- ACN is not a pavement design procedure.

***ACN/PCN System - Limitations***

## ACN/PCN System - Limitations

***ACN/PCN System - Limitations***

- Airplanes are represented by only one gear

## ACN/PCN System –Flexible PavementOne Gear versus All Gears (06 alphas)

## Westergaard solution for loaded elastic plate on a Winkler foundation
Interior load  (PCA method)
Concrete working stress = 2.75 MPa (399 psi)
4 Subgrade strengths
		High (A)	= 	150 MN/m3 (554 pci )
		Medium (B)	= 	80 MN/m3 (296 pci )
		Low (C)	= 	40 MN/m3 (148 pci )
		Ultra low (D)	= 	20 MN/m3 (74 pci )

- Westergaard solution for loaded elastic plate on a Winkler foundation
- Interior load  (PCA method)
- Concrete working stress = 2.75 MPa (399 psi)
- 4 Subgrade strengths
- 		High (A)	= 	150 MN/m3 (554 pci )
- 		Medium (B)	= 	80 MN/m3 (296 pci )
- 		Low (C)	= 	40 MN/m3 (148 pci )
- 		Ultra low (D)	= 	20 MN/m3 (74 pci )

***ACN/PCN System – ******Rigid Pavement***

## California Bearing Ratio (CBR) Method
4 Subgrade Strengths
		High (A) 	= 	CBR 15
		Medium (B)	= 	CBR 10
		Low (C)	= 	CBR 6
		Ultra low (D)	= 	CBR 3

- California Bearing Ratio (CBR) Method
- 4 Subgrade Strengths
- 		High (A) 	= 	CBR 15
- 		Medium (B)	= 	CBR 10
- 		Low (C)	= 	CBR 6
- 		Ultra low (D)	= 	CBR 3

***ACN/PCN System –******Flexible Pavement***

## A Derived Single Wheel load (DSWL) at 1.25 MPa (181 psi) is computed for each subgrade.
Found by equating thickness for DSWL to design thickness for airplane gear

ACN = DSWL in kilograms divided by 500
      Calculated at maximum main gear loading – i.e. maximum ramp weight and corresponding maximum center of gravity

- A Derived Single Wheel load (DSWL) at 1.25 MPa (181 psi) is computed for each subgrade.
- Found by equating thickness for DSWL to design thickness for airplane gear
- ACN = DSWL in kilograms divided by 500
-       Calculated at maximum main gear loading – i.e. maximum ramp weight and corresponding maximum center of gravity

***ACN/PCN System ***

## =

***Historic Flexible Design Parameter******Derived Single Wheel Load (DSWL)***

- Load at Max CG

- DSWL

- Equal Deflection

- Compute DSWL so
- subgrade deflection
- is equal

- Defined Tire Pressure 181 psi

- Airplane Operating Tire Pressure ?? psi

## Official ACN values are provided by the Aircraft Manufacturer

Airplane Characteristics for Airport Planning

- _Official_ ACN values are provided by the Aircraft Manufacturer
*Airplane Characteristics for Airport Planning*

***ACN/PCN System – ******Official ACN***

## Airplane Characteristics manual report official center of gravity and max gross load for ACN calculation.

Tire pressure (used in ACN calculation) is also reported for standard configuration

- Tire pressure (used in ACN calculation) is also reported for standard configuration

***ACN/PCN System***

## FAA Guidance on ACN-PCN

***FAA Guidance on ACN-PCN***

- AC 150/5335-5A  *STANDARDIZED METHOD OF REPORTING AIRPORT PAVEMENT STRENGTH – PCN*
- AC introduces the COMFAA program.
- COMFAA can be used to calculate ACN values for any airplanes.
- Manufacturer’s have provided CG and max load data for ACN determination.

## COMFAA 2.0 Program

## Case Study

## ACN-PCN – Case Study

***ACN-PCN – Case Study***

- Consider the following pavement section
- Category B subgrade support

**P-501 Concrete**

**Effective Support**

-  Existing thickness = 18.25 inches
- Flexural Strength = 700 psi,
- Effective K-value = 323 pciSections comprised of P-304 and P-155

## ACN-PCN – Case Study

***ACN-PCN – Case Study***

- Traffic Information
- Airplanes used to design original pavement section

| AIRPLANE | Gross Wt lbs | Annual Departures |
| --- | --- | --- |
| A300-b4 std | 375,000 | 3,102 |
| B737-700 | 174,700 | 111,952 |
| A380 basic body | 1,235,000 | 75 |
| A380 basic wing | 1,235,000 | 75 |
| B727-100 alt | 172,000 | 382 |
| B737-400 | 150,500 | 83,884 |
| B747-400 | 873,000 | 918 |
| B757-200 | 250,000 | 19,851 |
| B787-8 | 478,000 | 9,875 |
| B777-300 baseline | 662,000 | 6,141 |
| DC8-63/73 | 358,000 | 299 |
| DC9-51 | 115,000 | 32 |
| DC-10-10 | 458,000 | 1,726 |
| MD-11ER | 621,000 | 166 |

## ACN-PCN – Case Study

***ACN-PCN – Case Study***

- Traffic Information

| AIRPLANE | Gross Wt lbs | Annual Departures | Individual Required Thickness In |
| --- | --- | --- | --- |
| A300-b4 std | 375,000 | 3,102 | 12.98 |
| B737-700 | 174,700 | 111,952 | 17.37 |
| A380 basic body | 1,235,000 | 75 | 10.60 |
| A380 basic wing | 1,235,000 | 75 | 11.59 |
| B727-100 alt | 172,000 | 382 | 12.02 |
| B737-400 | 150,500 | 83,884 | 15.58 |
| B747-400 | 873,000 | 918 | 12.29 |
| B757-200 | 250,000 | 19,851 | 11.44 |
| B787-8 | 478,000 | 9,875 | 14.93 |
| B777-300 baseline | 662,,000 | 6,141 | 12.66 |
| DC8-63/73 | 358000 | 299 | 11.58 |
| DC9-51 | 115,000 | 32 | 9.3 |
| DC-10-10 | 458,000 | 1,726 | 12.06 |
| MD-11ER | 621,000 | 166 | 11.96 |

- Thickest Requirement

**Per current procedure – this would become the “design” airplane**

## ACN-PCN – Case Study

***ACN-PCN – Case Study***

- Traffic Information – Determine Equivalent Annual Departures

| AIRPLANE | Gross Wt lbs | Annual Departures | Equivalent Annual Departures |
| --- | --- | --- | --- |
| A300-b4 std | 375,000 | 3,102 | 6,568 |
| B737-700 | 174,700 | 111,952 | 111,952 |
| A380 basic body | 1,235,000 | 75 | 288 |
| A380 basic wing | 1,235,000 | 75 | 444 |
| B727-100 alt | 172,000 | 382 | 365 |
| B737-400 | 150,500 | 83,884 | 37,150 |
| B747-400 | 873,000 | 918 | 3,369 |
| B757-200 | 250,000 | 19,851 | 6,292 |
| B787-8 | 478,000 | 9,875 | 79,079 |
| B777-300 baseline | 662,000 | 6,141 | 49,310 |
| DC8-63/73 | 358,000 | 299 | 503 |
| DC9-51 | 115,000 | 32 | 17 |
| DC-10-10 | 458,000 | 1,726 | 8,458 |
| MD-11ER | 621,000 | 166 | 755 |

- Total equivalent annual departures   = 304,550

## ACN-PCN – Case Study

***ACN-PCN – Case Study***

- Traffic Information

- Allowable load of B737-700 with 304,550 annual departures to match existing 18.25 inch PCC
- 	From COMFAA
- 		Load = 174,700 lbs

## ACN-PCN – Case Study

***ACN-PCN – Case Study***

- Traffic Information

- PCN value for the following conditions
- 	Design Airplane = B737-700 at 174,700 lbs
- 	Equiv. Annual Departures = 304,550
- 	Category B subgrade
- PCN = 51/R/B/W/T

## ACN-PCN – Case Study

***ACN-PCN – Case Study***

- Traffic Information

- PCN = 51/R/B/W/T
- However,  several airplanes included in the original pavement design will exceed this PCN.
- For example, the B777-300 has a ACN range of 28 – 68
- To meet the 51/R/B rating the B777-300 would be weight restricted to 547,000 lbs  (reduced by 115,000 lbs from pavement design weight)

## ACN-PCN – Case Study

***ACN-PCN – Case Study***

- Traffic Information – ACN for each airplane

| AIRPLANE | Gross Wt lbs | Annual Departures | ACN/R/B |
| --- | --- | --- | --- |
| A300-b4 std | 375000 | 3102 | 59.2 |
| B737-700 | 174700 | 111952 | 50.5 |
| A380 basic body | 1235000 | 75 | 67.7 |
| A380 basic wing | 1235000 | 75 | 66.8 |
| B727-100 alt | 172000 | 382 | 49.2 |
| B737-400 | 150500 | 83884 | 44.5 |
| B747-400 | 873000 | 918 | 62.6 |
| B757-200 | 250000 | 19851 | 35.5 |
| B787-8 | 478000 | 9875 | 68.3 |
| B777-300 baseline | 662000 | 6141 | 68.9 |
| DC8-63/73 | 358000 | 299 | 60.0 |
| DC9-51 | 115000 | 32 | 34.2 |
| DC-10-10 | 458000 | 1726 | 56.4 |
| MD-11ER | 621000 | 166 | 67.7 |

- Indicates some reduction in operation weight would be required if a PCN of 51 is selected.

## ACN-PCN – Case Study

***ACN-PCN – Case Study***

- Traffic Information – ACN for each airplane

| DESIGN AIRPLANE | Allowable Gross Wt lbs | Equivalent Annual Departures | ACN/R/B |
| --- | --- | --- | --- |
| A300-b4 std | 433,500 | 131,949 | 73.1 |
| B737-700 | 174,700 | 304,550 | 50.5 |
| A380 basic body | 1,673,000 | 27,823 | 110.2 |
| A380 basic wing | 1,485,000 | 36,083 | 85.1 |
| B727-100 alt | 185,000 | 331,849 | 53.7 |
| B737-400 | 163,000 | 714,859 | 49.0 |
| B747-400 | 1,032,200 | 63,056 | 79.6 |
| B757-200 | 338,000 | 1,308,008 | 54.7 |
| B787-8 | 549,000 | 41,707 | 83.2 |
| B777-300 baseline | 875,000 | 39,457 | 109.0 |
| DC8-63/73 | 409,000 | 167,329 | 72.8 |
| DC9-51 | COMFAA limit | 3,998,329 | COMFAA limit |
| DC-10-10 | 590,000 | 50,534 | 80.3 |
| MD-11ER | 738,000 | 35,206 | 86.4 |

- PCN values determined by treating each airplane as the design airplane

*Airplane weights may exceed practical limits*

**?**

## ACN-PCN – Case Study

***ACN-PCN – Case Study***

- Traffic Information – FAARFIELD Analysis

- 17.5 LED design thickness

| Airplane | Gross Wt.  lbs | AnnualDepartures | CDFContribution | CDF Maxfor airplane |  | CDFContribution | CDF Maxfor airplane |
| --- | --- | --- | --- | --- | --- | --- | --- |
| A300-B4 std | 375,000 | 3,102 | 0.02 | 0.07 |  | 0.02 | 0.02 |
| B737-700 | 174,700 | 100,000 | 0.81 | 0.84 |  | 0.01 | 0.18 |
| B737-700 | 174,700 | 1,952 | 0.02 | 0.02 |  | 0.00 | 0.00 |
| B727-100C Alt | 172,000 | 382 | 0.00 | 0.00 |  | 0.00 | 0.00 |
| B737-400 | 150,500 | 83,884 | 0.05 | 0.06 |  | 0.00 | 0.01 |
| B747-400 | 873,000 | 918 | 0.02 | 0.04 |  | 0.01 | 0.01 |
| B757-200 | 250,000 | 19,851 | 0.00 | 0.00 |  | 0.00 | 0.00 |
| B787-8 | 478,000 | 9,875 | 0.04 | 0.51 |  | 0.16 | 0.16 |
| B777-300 Baseline | 662,000 | 6,141 | 0.01 | 0.27 |  | 0.08 | 0.09 |
| DC8-63/73 | 358,000 | 299 | 0.01 | 0.01 |  | 0.00 | 0.00 |
| DC9-51 | 115,000 | 32 | 0.00 | 0.00 |  | 0.00 | 0.00 |
| DC10-10 | 458,000 | 1,726 | 0.00 | 0.01 |  | 0.00 | 0.00 |
| MD11ER | 621,000 | 166 | 0.00 | 0.01 |  | 0.00 | 0.00 |
| MD11ER Belly | 621,000 | 166 | 0.00 | 0.02 |  | 0.00 | 0.01 |
| A380 1 Body | 1,235,000 | 75 | 0.00 | 0.00 |  | 0.00 | 0.00 |
| A380 1 Wing | 1,235,000 | 75 | 0.00 | 0.00 |  | 0.00 | 0.00 |

- 18.25 existing thickness

## Questions or Comments?