The objective of this task is to develop a mix design procedure for the various types of FDR

Determine what works and what does not work

Each type of FDR has separate mix design

◦ Unstabilized◦ Mechanically stabilized: add virgin aggregate◦ Stabilized FDR with Portland Cement◦ Stabilized FDR with Fly Ash◦ Stabilized FDR with Asphalt Emulsion◦ Stabilized FDR with Asphalt Emulsion with 1% Lime◦ Stabilized FDR with Foamed Asphalt with 1% Portland

Cement

◦ Source: Good and Poor

◦ Quality: Dirty and Clean

◦ RAP: 0, 25, 50, and 75%

FDR Source GradationFDR Type

Unstabilized Stabilized with PC (3, 5, 7 %)

Stabilized with Fly Ash (10, 12, 15 %)

Stabilized with Asphalt Emulsion

(3, 4.5, 6 %)

Stabilized with Asphalt Emulsion (3, 4.5, 6 %)+ Lime

Stabilized with Foamed Asphalt

(2.5, 3, 3.5 %) + PC

Good

Clean

-Moisture-density -Mr and CBR

-Moisture-density - Comp strength-Moisture sensitivity

-Moisture-density- Comp strength-Moisture sensitivity

-Moisture-DensitySuperpave Gyratory- Density with Corelok-Moisture sensitivity

-Moisture-Density-Superpave Gyratory- Density with Corelok-Moisture sensitivity

-Moisture-Density-Superpave Gyratory-Density with Corelok-Moisture sensitivity

DirtySAME SAME SAME SAME SAME SAME

Poor

CleanSAME SAME SAME SAME SAME SAME

Dirty

SAME SAME SAME SAME SAME SAME

Strength: ◦ Mr and CBR for unstabilized ◦ UC for cement and fly ash stabilized◦ TS for foamed and emulsion stabilized

Moisture Susceptibility ◦ Tube Suction and ASTM D559

For cement and fly ash stabilized ◦ AASHTO T-283

for foamed and emulsion stabilized

What works and what does not

What criteria to implement

Repeatability and reliability

Does the measurement make engineering sense

RAP 25 and 50% content did not significantly impact the Mr

The 75% RAP improved the Mr of the Poor source

Relationship between Mr and CBR is un-reliable for FDR: Use Mr

FDR+PC & FDR+FA◦ Dry UC: 300 – 400 psi◦ Tube Suction: max 9

FDR+Foamed & FDR+Emulsion◦ Dry TS at 77F: min 30 psi◦ TS Ratio: min. 70%

Material - %Rap %PC Dry UC (psi) Tube Suction

GC-25% 5 283 4.6

GC-50% 7 407 4.6

GC-75% 7 409 3.9

GD-25% 3 352 6.3

GD-50% 5 413 5.3

GD-75% 7 374 5.9

PC-25% 3 295 6.2

PC-50% 5 379 4.0

PC-75% 5 256 7.1

PD-25% 3 454 5.5

PD-50% 3 421 3.0

PD-75% 5 409 3.6

UC strength between 300 and 400 psi is achievable in most cases

Higher UC with higher PC content in all cases

Variability of the UC test is acceptable

Tube Suction test maybe applicable

Good Clean 75% Rap 7% Cem

2030

2035

2040

2045

2050

2055

0 2 4 6 8 10 12 14

Cycles

Wei

ght (

gm)

Poor Dirty 50% Rap 3% CEM

1800

1850

1900

1950

2000

2050

2100

2150

0 2 4 6 8 10 12 14

Cycles

Wei

ght (

gm)

Material -% Rap %FA Dry UC (psi) Tube Suction

GC-25% 12 895 5.1

GC-50% 12 362 4.1

GC-75% 12 335 4.6

GD-25% 10 579 10.6

GD-50% 10 412 7.1

GD-75% 12 330 9.2

PC-25% 10 558 6.0

PC-50% 12 404 6.5

PC-75% 12 327 5.7

PD-25% 15 170 6.9

PD-50% 15 159 9.8

PD-75% 15 63 9.2

UC strength between 300 and 400 psi is achievable except for the Poor-Dirty material

Higher UC with higher FA in most cases

Variability of the UC is acceptable

Tube Suction test maybe applicable

Good Dirty 50% Rap 10% FA

1760

1780

1800

1820

1840

1860

1880

1900

0 2 4 6 8 10 12 14Cycles

Wei

ght (

gm)

Poor Clean 75% Rap 10% FA

1930

1935

1940

1945

1950

1955

1960

1965

1970

0 2 4 6 8 10 12 14Cycles

Wei

ght (

gm)

Material –%Rap %Emulsion Dry TS(psi) Wet TS(psi) TSR (%)

NO LIME

GD-25% 4.5 41 15 37

GD-50% 4.5 47 20 43

GD-75% 4.5 46 21 46

PD-25% 4.5 30 Disintegrate

PD-50% 4.5 50 Disintegrate

PD-75% 4.5 51 Disintegrate

1% LIME

GD-25% 4.5 45 27 60

GD-50% 4.5 37 32 86

GD-75% 4.5 44 31 70

PD-25% 4.5 22 13 59

PD-50% 4.5 38 17 45

PD-75% 4.5 34 19 56

Could not design the clean materials: too little fines

The TS is a good indicator

The repeatability of the TS is very good

Lime was effective

Material - %Rap

%AC Dry TS(psi) Wet TS(psi) TSR (%)

GC-25% 3.0* 53 43 81

GC-50% 3.0* 51 41 80

GC-75% 3.0* 58 45 78

GD-25% 3.5 45 34 76

GD-50% 3.5 44 43 98

GD-75% 3.5 51 42 82

PC-25% 3.5 54 32 59

PC-50% 3.5 53 40 75

PC-75% 3.5 48 33 69

PD-25% 3.0 43 26 60

PD-50% 3.0 48 29 60

PD-75% 3.0 55 35 64

Could not design without the PC

The TS is a good indicator

The repeatability of the TS is very good

Be consistent with AASHTO Design Guides

◦ AASHTO 1993

◦ AASHTO MEPDG

Unstablised: Resilient modulus (Mr)

FDR+PC & FDR+FA: Modulus of Rupture (MR)

FDR+Foamed & FDR+Emuslion: Dynamic Modulus (E*)

Material - %Rap %PC Dry UC (psi) MR (psi)

GC-25% 5 283 70

GC-50% 7 407 135

GC-75% 7 409 117

GD-25% 3 352 64

GD-50% 5 413 86

GD-75% 7 374 122

PC-25% 3 295 55

PC-50% 5 379 96

PC-75% 5 256 95

PD-25% 3 454 55

PD-50% 3 421 72

PD-75% 5 409 79

Material - %Rap %FA Dry UC (psi) MR (psi)

GC-25%Rap 12 895 70

GC-50%Rap 12 362 36

GC-75%Rap 12 335 25

GD-25%Rap 10 579 58

GD-50%Rap 10 412 35

GD-75%Rap 12 330 25

PC-25%Rap 10 558

PC-50%Rap 12 404 28

PC-75%Rap 12 327

PD-25%Rap 15 170 23

PD-50%Rap 15 159 9

PD-75%Rap 15 63 48

|E*| master curve: Modulus of HMA at any combination of loading rate & temperature .

Time

Str

ess

Str

ain

Time

time shift = /

= 0sin(ωt)

= 0sin(ωt-)

0

0

|E*| = σ0/ε0

34

0.01

0.1

1

10

1.0E-05 1.0E-03 1.0E-01 1.0E+01 1.0E+03 1.0E+05Frequency, Hz

E* ,

103 k

si

.