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
.