AAR-410 02/13/031 FAA Airport Pavement Technology Program u Testing and preliminary data analysis...

02/13/03 1 AAR-410

FAA Airport PavementFAA Airport PavementTechnology ProgramTechnology Program

Testing and preliminary data analysis from flexible pavements on low-strength subgrade (Construction Cycle Three (CC3)).

Current work and plans for next rigid pavement test items.

02/13/03 2 AAR-410

P -401

P -209

P -154

P -154

P -154P -154

80 ft 20 ft60 ft

60 ft40 ft

Low-Strength SG Flexible Low-Strength SG Flexible Replacement – Fall 2002Replacement – Fall 2002

200Target Repetitions to Failure

11,000770 3,500

Thicknesses are based on 55,000 lb wheel load on 3 CBR subgrade.

5-in thick

8-in thick

43-in (110-cm) thick

34-in (85-cm) thick

24-in (60-cm) thick

16-in (40-cm) thick

6-Wheel

4-Wheel 370 2000 11,800 36,400

LFC1

LFC2

LFC3 LFC4

02/13/03 3 AAR-410

Low-Strength SG ReworkLow-Strength SG Rework

02/13/03 4 AAR-410

Design MethodologyDesign Methodology

LEDFAA with 2-layer subgrade. Vary Poisson’s Ratio with subgrade strength:

Poisson’s Ratio = 0.82 – 0.1 * (logESG/145).

Improve behavior of failure model at low departure levels:

log v = – 2.301 – 0.1607 log CF (Super-Heavy Aircraft

Study).

02/13/03 5 AAR-410

Design ConditionsDesign Conditions

Reworked subgrade CBR = 3 Existing subgrade CBR = 5.5 Wheel load = 55,000 lbs Dual spacing = 54 inches (4- and 6-wheel) Tandem spacing = 57 inches (4- and 6-

wheel)

02/13/03 6 AAR-410

LFC3 – Reworked Subgrade LFC3 – Reworked Subgrade = 3 CBR= 3 CBR

02/13/03 7 AAR-410

Variation of Asphalt Modulus Variation of Asphalt Modulus with Temperature (Witczak)with Temperature (Witczak)

1446225

1069375

764216

527830

352342

227314

141736

0

200000

400000

600000

800000

1000000

1200000

1400000

1600000

0 20 40 60 80 100 120

Temperature, deg. F

AC

Mod

ulus

, psi

02/13/03 8 AAR-410

Variation of Pavement Life Variation of Pavement Life with Temperature – LFC3, with Temperature – LFC3, from LEDFAAfrom LEDFAA

0

500

1000

1500

2000

2500

0 10 20 30 40 50 60 70 80 90 100

Pavement Temperature, deg. F

Num

bner

of

Pass

es to

Fai

lure

4-Wheel Gear

6-Wheel Gear

350-600 and 1200-2100

02/13/03 9 AAR-410

Testing ScheduleTesting Schedule September 3: started. September 4: stopped testing on LFC1. September 6: 990 passes. September 12: stopped testing on LFC2 at 3,168

passes. September 13 and 16: 2 test pits in LFC2. September 17: tried MWHGL wander on LFC3

and 4. September 18: increased load to 65,000 and

continued testing on LFC3 and 4 with old wander. October 18: stopped at 23,826 passes.

02/13/03 10 AAR-410

Asphalt TemperaturesAsphalt Temperatures

60

65

70

75

80

85

90

1 21 41 61 81

101

121

141

161

181

201

221

241

261

281

301

321

341

361

381

401

421

441

461

481

501

521

541

561

581

601

621

641

661

681

701

721

One-hour intervals from 0:00 Sunday September 1 to 23:00 Monday 30, 2002

P-4

01 T

emp

erat

ure

s, d

egre

es F

LFC3 NA

LFC3 NB

LFC3 NC

LFC3 SA

Surface 1

LFC3 SC

Time

02/13/03 11 AAR-410

Pavement at 19,500 PassesPavement at 19,500 Passes

02/13/03 12 AAR-410

North, 6-Wheel TrackNorth, 6-Wheel Track

02/13/03 13 AAR-410

South, 4-Wheel TrackSouth, 4-Wheel Track

02/13/03 14 AAR-410

Rut Depths from StraightedgeRut Depths from StraightedgeCC-3 RUT DEPTH MEASUREMENTS

0.1

1

10

10 100 1000 10000 100000

Passes

Rut

Dep

th, i

nch

LFC-1:North LFC-1:South




Tried different wander. Then increased load to 65,000 lbs

02/13/03 15 AAR-410

Rut Depths from StraightedgeRut Depths from StraightedgeCC-3 RUT DEPTH MEASUREMENTS

0

1

2

3

4

5

6

7

8

10 100 1000 10000 100000

Passes

Rut

Dep

th, i

nch





Tried different wander. Then increased load to 65,000 lbs

02/13/03 16 AAR-410

LFC3 - Upheaval on North TrackLFC3 - Upheaval on North Track

02/13/03 17 AAR-410

LFC3 - Upheaval on South TrackLFC3 - Upheaval on South Track

02/13/03 18 AAR-410

Laser Profiler – 21.5 ft Span, Laser Profiler – 21.5 ft Span, 8 in Range8 in Range

02/13/03 19 AAR-410

Transverse Profile – LFC3 Transverse Profile – LFC3 ~1,000 Pass Intervals~1,000 Pass Intervals

02/13/03 20 AAR-410

Failure Criteria for Flexible Failure Criteria for Flexible Design Design From MWHGL Report. A pavement was considered failed

when either of the following conditions occurred: Surface upheaval of the pavement adjacent

to the traffic lane reached 1 in. or more. Surface cracking occurred to the point that

the pavement was no longer waterproof.

02/13/03 21 AAR-410

Rut Depths from ProfilesRut Depths from ProfilesLFC1 - Maximum Rut Depth from Profile Measurements

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

0 20 40 60 80 100 120 140

Passes

De

pth

, in

ch

es

LFC1N1 LFC1N2 LFC1NC

LFC1S1 LFC1S2 LFC1SC

02/13/03 22 AAR-410

Uplift from ProfilesUplift from ProfilesLFC1 - Right Uplift from Profile Measurements

-1.2

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0 20 40 60 80 100 120 140

Passes

Lif

t, in

ch

es



02/13/03 23 AAR-410

Rut Depth from ProfilesRut Depth from ProfilesLFC2 - Maximum Rut Depth from Profile Measurements

0

1

2

3

4

5

6

7

8

9

0 500 1000 1500 2000 2500 3000

Passes

Ru

t D

ep

th, i

nc

he

s



02/13/03 24 AAR-410

Uplift from ProfilesUplift from ProfilesLFC2 - Left Uplift from Profile Measurements

-1.4

-1.2

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0 500 1000 1500 2000 2500 3000

Passes

Up

lift,

inc

he

s



02/13/03 25 AAR-410

Uplift from ProfilesUplift from Profiles LFC2 - Right Uplift from Profile Measurements

-1.2

-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0 500 1000 1500 2000 2500 3000

Passes

Up

lift,

inc

he

s



02/13/03 26 AAR-410

Rut Depth from Profiles - ExtrapolatedRut Depth from Profiles - Extrapolated LFC2 - Maximum Rut Depth from Profile Measurements

0

1

2

3

4

5

6

7

8

9

0 500 1000 1500 2000 2500 3000

Passes

Ru

t D

ep

th, i

nc

he

s

LFC2N1 LFC2N2 LFC2NCLFC2S1 LFC2S2 LFC2SCExtrapN ExtrapS ExtrapN0ExtrapS0

02/13/03 27 AAR-410

CC3 and CC1-MFC Compared CC3 and CC1-MFC Compared to MWHGLto MWHGL

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1.4

1.0E+00 1.0E+01 1.0E+02 1.0E+03 1.0E+04 1.0E+05

Aircraft Traffic Volume Factor, Coverages

Lo

ad

Re

pe

titi

on

Fa

cto

r, A

lph

a

12-Wheel Failure

12-Wheel Nonfailure

50-kip Single Wheel Failure

30-kip Single Wheel Failure

30-kip Single Wheel Nonfailure

Dual-Tandem Failure

NAPTF 4-Wheel

NAPTF 6-Wheel

Alpha = 0.23 log C + 0.15

Single Wheel

Twin Tandem

12 Wheels

Preliminary Data

02/13/03 28 AAR-410

MWHGL DT Test ItemMWHGL DT Test Item

B-747 gear, 60,000 lb wheel loads, failed at 420 passes.

02/13/03 29 AAR-410

Layered Elastic StrainLayered Elastic Strain SUBGRADE VERTICAL STRAIN & NUMBER OF COVERAGES

ONLY SUBGRADE FAILURE CONSIDERED

y = 0.0057x-0.1462

R2 = 0.6581

0.0001

0.001

0.01

1 10 100 1,000 10,000 100,000 1,000,000

No. of Coverages to Failure

Ver

tica

l Su

bgr

ade

Str

ain

, in

ch/i

nch

StocktonMWHGLStructural Layers StudyBoeing-Russia-ClaySan AntonioNAPTF

MFC B-747

MFC B-777

Boeing/RussiaB-747 ClayBoeing/Russia

B-777 Clay

LFC B-777

LFC B-747

CC3-LFC1-6W

CC3-LFC1-4W

CC3-LFC2-6W

CC3-LFC2-4W

02/13/03 30 AAR-410

Starting Excavation of TrenchStarting Excavation of Trench

02/13/03 31 AAR-410

Current Proposal for Rigid Current Proposal for Rigid Reconstruction (1)Reconstruction (1) 15 ft x 15 ft (4.5 m x 4.5 m) slabs. 3-Part optimized mix. 28-day wet burlap cure. Transverse joints doweled.

02/13/03 32 AAR-410

Current Proposal for Rigid Current Proposal for Rigid Reconstruction (2)Reconstruction (2)

Looked at decreasing strength and increasing thickness: Rounded intermediate aggregate, no

significant decrease. 30%, and 50% Class C flyash replacement

in a two-part mix (batched 1/13/03), significant decrease at 50%.

02/13/03 33 AAR-410

PCC Beam StrengthsPCC Beam StrengthsCC-2 MIX DESIGNS - BEAMS

0

200

400

600

800

1000

1200

0 7 14 21 28 35

Concrete Age, days

Mod

ulu

s of

Ru

ptu

re, p

si

Rounded Aggregate-1 (Original)Rounded Aggregate-2 (Original)30% Fly Ash -130% Fly Ash -250% Fly Ash -150% Fly Ash -2

02/13/03 34 AAR-410

PCC Cylinder StrengthsPCC Cylinder StrengthsCC-2 MIX DESIGNS - CYLINDERS

0

1000

2000

3000

4000

5000

6000

0 7 14 21 28 35

Concrete Age, days

Com

pre

ssiv

e S

tren

gth

, psi

Rounded Aggregate-1 (Original)Rounded Aggregate-2 (Original)30% Fly Ash -130% Fly Ash -250% Fly Ash -150% Fly Ash -2

02/13/03 35 AAR-410

Flexural vs. CompressiveFlexural vs. CompressiveCC-2 MIX DESIGNS

Relationship Between Compressive Strength & Modulus of Rupture

0

200

400

600

800

1000

1200

1400

1600

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

Compressive Strength, psi

Mod

ulu

s of

Ru

ptu

re, p

si

02/13/03 36 AAR-410

Current Proposal for Rigid Current Proposal for Rigid Reconstruction (3)Reconstruction (3) One more batch at 70% flyash

replacement. 15 ft x 15 ft x 11 in thick test slab on

existing PCC. Will measure. Vertical displacement of corners. Horizontal strains. Temperature through depth. Relative humidity through depth.

02/13/03 37 AAR-410

Current Proposal for Rigid Current Proposal for Rigid Reconstruction (4)Reconstruction (4) Three test items on medium-strength

subgrade: Existing econocrete subbase. Aggregate subbase. Slab-on-subgrade.

Rebuilding medium strength subgrade to depth of 3 feet. Target strength is 7 CBR. Half finished.

AAR-410 02/13/031 FAA Airport Pavement Technology Program u Testing and preliminary data analysis...

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