TPF-5(230) Evaluation of Plant Evaluation of Plant-Produced

TPF-5(230)
TPFEvaluation of PlantPlant-Produced
High--Percentage RAP Mixtures
High
in the Northeast
Thomas Bennert, Ph.D.
R t
Rutgers
University
U i
it
CAIT
RUTGERS
October 27th, 2011
Mercer County College, NJ
Research Team
Rutgers University
Dr. Thomas Bennert
University of New Hampshire
Dr. Jo Sias Daniel
U i
University
it off Massachusetts
M
h tt Dartmouth
D t
th
Dr. Walaa Mogawer
CAIT
RUTGERS
Participating Agencies

New Hampshire (NHDOT) - Lead Agency

Maryland (MDOT)

New Jersey (NJDOT)

New York (NYSDOT)

Pennsylvania (PennDOT)

Rhode Island (RIDOT)

Vi i i (VDOT)
Virginia

Federal Highway Administration (FHWA)
CAIT
RUTGERS
Project Objectives

Evaluate the performance of plant-produced RAP
mixtures (in the laboratory and field) in terms of
low temperature cracking, fatigue cracking,
stiffness, and moisture sensitivity.

Understand how asphalt plant production
i fl
influences
th
the properties
ti off RAP mixtures
i t
CAIT
RUTGERS
Project Timeline
Year 1: Production of Phase I mixtures, laboratory
testing,
g, data analysis.
y
Mixes having
g different
PG grades.
Year 2: Phase II mixtures produced,
produced continuation of
testing, data analysis, and construction of
field sections. Mixes having different PG
grades
d and
d “bi
“binder
d credit”.
dit”
Year 3: Final Phase II mixtures produced,
produced completion
of testing, monitoring field sections, data
analysis and synthesis, and preparation of
final report.
report
CAIT
RUTGERS
Research - Phase I

18 mixtures

Evaluate the effect of plant type and binder
grade on the properties of RAP mixtures

Mixtures with different PG grade asphalts from
the same plant at particular RAP percentages
were collected for direct evaluation of the effect
of binder grade. This was done for batch and
drum plants.
CAIT
RUTGERS
Phase I Experimental Plan
Plant Produced
RAP Mixtures
1. Discharge Temp.
2. Storage Time
3. Plant Type
4. Other
Document
Mixture
Production Data
Mixtures
N Y
New
York
k
PG58-28
PG64-22
RAP Percentages
0, 20, 30, 40
((PG58-28: 30,, 40 Only)
y)
CAIT
RUTGERS
N H
New
Hampshire
hi
PG64-28
RAP Percentages
0, 20, 30, 40
Testing & Analysis
V
Vermont
t
PG52-34
PG64-28
RAP Percentages
0, 20, 30, 40
Phase I Testing Plan - Binders
Test
Performance Grade
Test Method/
Reference
f
AASHTO R29 &
AASHTO M320
Lab
Rutgers
Binder Modulus and
Master Curve
n/a
UMass Dartmouth
Softening Point
AASHTO T53
Rutgers
Thermal Cracking
Temperature
Asphalt Binder
Cracking Device
UM
UMass
Dartmouth
D
h
Critical Cracking
Temperature
AASHTO R49
R49-09
09
Rutgers
CAIT
RUTGERS
Phase I Testing Plan Mixtures Plant Compacted and Reheated
Test
Dynamic Modulus
Low Temperature Creep and
Strength
Push-Pull Fatigue Test
((S-VECD))
Moisture Sensitivity
M i t S
Moisture
Sensitivity
iti it
CAIT
RUTGERS
Test Method/
Reference
AASHTO TP62
AASHTO TP79
Rutgers
NCSU
AASHTO T322
UNH
n/a
UNH
NCSU
AASHTO T283
UNH
AASHTO T324
UMass
Dartmouth
Lab
Additional Mixture Testing



Overlay Tester (fatigue testing)
Flexural Beam Fatigue (fatigue testing)
UMass Dartmouth Asphalt Workabilityy Device
CAIT
RUTGERS
Phase I Mixture Data
Producer
Callanan
NY
Pike
VT
Plant Type
Drum
Batch
Drum
CAIT
Pike
NH
RUTGERS
NMAS
PG grade % RAP
(mm)
40
58-28
30
40
12.5
30
64 22
64-22
20
0
40
30
52-34
20
0
9.5
40
30
64-28
20
0
40
30
12.5
64-28
20
0
RAP
% ac
4.9
4.93
4.9
4.93
4.95
-5.41
5 41
5.41
5.41
-5.41
5.41
5.41
-4.79
4.79
4.79
--
Total
% ac
5.2
5.2
5.2
5.2
5.2
5.2
6.6
66
6.6
6.8
6.7
6.6
6.6
6.7
6.5
5.7
5.7
5.7
5.7
% Binder
Replacement
37.7
28.4
37.7
28.4
19.0
0.0
32.6
24 7
24.7
16.0
0.0
33.0
24.6
16.1
0.0
33.6
25.2
16.8
0.0
VMA
VFA
12.7
13.7
12.5
13.0
14.1
12.6
18.0
17 7
17.7
18.7
20.2
18.2
19.1
18.7
20.3
14.5
14.4
14.5
14.9
88.4
81.1
87.9
85.1
79.9
89.3
77.8
82 5
82.5
81.9
76.3
76.4
75.9
79.7
71.5
82.1
81.3
79.9
74.8
Phase I Production Data
Producer
Plant Type
NMAS
(mm)
PG grade % RAP
58 28
58-28
Callanan
NY
Drum
12.5
64-22
52-34
Pike
VT
Batch
9.5
64-28
Pike
NH
Drum
CAIT
RUTGERS
12.5
64-28
40
30
40
30
20
0
40
30
20
0
40
30
20
0
40
30
20
0
Silo Storage Time Discharge
(hrs)
Temp. (F)
4.0
330
3.5
305
3.0
330
2.75
305
0 75
0.75
320
2.75
310
0.0
300
0.0
320
00
0.0
324
0.0
340
0.0
295
0.0
322
00
0.0
300
0.0
330
0.0
335
1.0
335
1 25
1.25
315
6.0
330
Compaction
Temp. (F)
275
275
290
290
290
290
295
320
324
340
295
310
300
300
315
315
310
300
Production Information – Callanan
Callanan,, NY
 Cedar Rapids
p counter flow
 Production
P d ti rates
t
drum plant.
p
approximately
i t l 250
tons per hour (tph) for the 30 and 40%
RAP mixtures and 300 tph for the virgin
and 20% RAP mixes.
CAIT
RUTGERS
Production Information – Pike, NH
 2008 Gencor Ultra
 400
drum plant.
tons per hour capacity.
 Mixing
times approximately 40
seconds.
d
CAIT
RUTGERS
Production Information – Pike, VT

Mixtures were produced in a 1966 H&B 5-ton drop
batch plant.
p

The batch p
plant mixing
g times and burner set
temperature varied depending on the RAP content:
 Virgin
Mix: 6 sec Dry Mix Time; 36 sec Wet Mix Time
 20% RAP: 10 sec Dry Mix Time; 36 sec Wet Mix Time
 30% RAP: 13 sec Dry Mix Time; 36 sec Wet Mix Time
 40% RAP: 13 sec Dry Mix Time; 36 sec Wet Mix Time
CAIT
RUTGERS
Phase I Binder Results
CAIT
RUTGERS
Extraction / Recovery of Binder

Binder from each p
plant p
produced mixture was
extracted in accordance with Method A of AASHTO
T164 “Quantitative Extraction of Asphalt Binder
f
from
Hot
H t Mix
Mi Asphalt
A h lt (HMA)”

Binder was then recovered in accordance with
AASHTO T170 “Recovery of Asphalt From Solution
by Abson Method”.
Method”
Extraction
E
t ti & Recovery
R
performed
f
d by
b Pike
Pik
CAIT
Industries, Inc.
RUTGERS

PG Grading Results
Continuous PG Grade (ºC)
Mixture
NY
58-28
NY
64 22
64-22
CAIT
RUTGERS
Type
High
Low
Inter.
PG Grade
Tank 7/30/10
60.3
-30.8
17.2
58-28
Tank 9/7/10
61.0
-34.6
18.5
58-34
Extracted 30% RAP
69.6
-28.2
21.3
64-28
Extracted 40% RAP
65.8
-29.3
20.5
64-28
Tank 7/30/10
67.3
-26.0
26.0
22.1
64-22
64
22
Tank 9/7/10
67.0
-25.5
21.9
64-22
Extracted 0% RAP
67.5
-26.7
22.2
64-22
E t t d 20% RAP
Extracted
69 3
69.3
-25.9
25 9
26 6
26.6
64 22
64-22
Extracted 30% RAP
70.9
-22.9
26.2
70-22
Extracted 40% RAP
74.0
-18.3
26.1
70-16
PG Grading Results
Continuous PG Grade (ºC)
Mixture
NH
64-28
CAIT
RUTGERS
Type
High
Low
Inter.
PG Grade
Tank
66.3
-29.5
19.9
64-28
E t t d 0% RAP
Extracted
66 8
66.8
-31.1
31 1
18 0
18.0
64 28
64-28
Extracted 20% RAP
67.9
-30.0
20.9
64-28
Extracted 30% RAP
70.6
-29.8
18.6
70-28
Extracted 40% RAP
70.3
-29
20.3
70-28
PG Grading Results
Continuous PG Grade
(ºC)
Mixture
Vermont
52-34
Vermont
64-28
CAIT
RUTGERS
Type
High
Low
Inter.
PG Grade
Tank
56.3
-32.5
12.1
52-28
Extracted 0% RAP
56.6
-30.1
10.3
52-28
Extracted 20% RAP
57.8
-31.4
11.9
52-28
Extracted 30% RAP
59.1
-32.0
11.2
58-28
Extracted 40% RAP
59.8
-32.8
12.4
58-28
Tank
64.4
-30.2
16.6
64-28
Extracted 0% RAP
61 7
61.7
-28.7
28 7
16 8
16.8
58 28
58-28
Extracted 20% RAP
60.9
-30.3
15.5
58-28
Extracted 30% RAP
63.0
-28.5
17.4
58-28
Extracted 40% RAP
61.9
-29.0
17.0
58-28
Binder Low Temperature Cracking

The low temperature cracking characteristics of the
recovered binders were evaluated due to concern that high
RAP content might lead to a very stiff mixture that is
susceptible
tibl tto th
thermall cracking.
ki
The effect of the RAP binder on the low temperature
cracking characteristics of the recovered binders was
evaluated utilizing three methods: the Asphalt Binder
C ki D
Cracking
Device
i (ABCD) (AASHTO TP92) and
d AASHTO R49
“Determination of Low-Temperature Performance Grade (PG)
of Asphalt Binders.”; Glass Transition analysis using 4mm
plate (Reinke)
CAIT

RUTGERS
Low Temperature Critical Cracking
g
4mm Tg
ABCD Device
18
52‐34 Virgin Williston, VT ‐ Fracture Strength & Thermal Stress
Critical Temperature = ‐34.5C
16
14
12
10
DTT
BBR
8
6
4
CAIT
RUTGERS
2
0
‐50
‐45
‐40
‐35
‐30
‐25
‐20
‐15
AASHTO R49
‐10
‐5
0
CAIT
RUTGERS
‐48
‐18
‐24
‐30
‐36
‐42
AASHTO R49
ABCD Device
4mm Tg (Reinke)
Extracted ‐ 40% RAP
Extracted ‐ 30% RAP
PG52‐34
Extracted ‐ 20% RAP
RAP
Extracted ‐ 0% R
Pike (Portsmouth, VT)
Extracted ‐ 40% RAP
Extracted ‐ 30% RAP
PG64‐28
Extracted ‐ 20% RAP
RAP
Extracted ‐ 0% R
Extracted ‐ 40% RAP
PG64‐22
Extracted ‐ 30% RAP
Callanan (NY)
Extracted ‐ 20% RAP
RAP
Extracted ‐ 0% R
Extracted ‐ 40% RAP
Extracted ‐ 30% RAP
PG58‐28
Extracted ‐ 20% RAP
RAP
Extracted ‐ 0% R
Extracted ‐ 40% RAP
Extracted ‐ 30% RAP
Low Temperature Critical Cracking
Pike (Williston, VT)
PG64‐28
Low Temp. - Observations



For the NY and VT mixtures, the data indicated the
softer binder improved the resistance to low
temperature cracking.
Since recovered binders represent full blending, the
data indicates that if good blending occurs in the
mixtures then a softer binder will help alleviate low
temperature cracking potential of the mixture.
mixture
There were major differences between the different
analysis procedures
 ABCD
is 7.9oC lower critical cracking temps than
AASHTO R49
 Reinke Tg analysis is 4.2oC lower critical cracking than
CAIT
RUTGERSAASHTO T49
Phase I Mixture Results
CAIT
RUTGERS
Moisture SusceptibilitySusceptibilityAASHTO T283
 All
mixtures exhibited TSR values of
80% or more
 No
observed trends with respect to
RAP content or binder grade
CAIT
RUTGERS
Moisture Susceptibility Hamburg Wheel Tracking Device (HWTD)
HWTD testing conducted in
accordance with AASHTO T324
Water temperature of 50ºC (104ºF)
during testing
Test duration of 20,000
,
cycles
y
CAIT
RUTGERS
Stripping Inflection Point (SIP)
CAIT
RUTGERS
NY HWTD Results
Binder
RAP %
RAP,
Discharge
Temp, F
Laydown
Temp, F
SIP
Avg. Rut Depth
at 10,000
10 000 Cycles
(mm)
0
310
290
7,200
6.62
20
320
290
20,000
1.93
30
305
290
13 400
13,400
2 67
2.67
40
330
290
20,000
1.55
30
305
275
17,400
2.63
40
330
275
20 000
20,000
2 12
2.12
PG 64-22
PG 58-28
CAIT
RUTGERS
NH HWTD Results
Laydown
Temp F
Temp,
SIP
Avg. Rut Depth
at 10,000
,
Cycles
y
(mm)
Binder
RAP,, %
Discharge
Temp F
Temp,
PG 64-28
0
330
300
20,000
2.15
PG 64-28
20
315
310
20,000
1.7
PG 64-28
30
335
315
20,000
0.49
PG 64-28
40
335
315
20,000
0.93
CAIT
RUTGERS
VT HWTD Results
Binder
PG 52
52-34
34
PG 64
64-28
28
CAIT
RUTGERS
RAP, %
Discharge
Temp, F
Laydown
Temp, F
SIP
0
315
315
700
20
324
324
1,600
30
320
320
2,050
40
300
295
1,450
0
330
300
1,350
20
300
300
2,100
30
322
310
2,650
40
295
295
2,900
No Silo Storage Time for Any of VT Mixes
Mixture Stiffness Properties
CAIT
RUTGERS
MIXTURE STIFFNESS –
Dynamic Modulus
Temperature
4 4C
4.4
C
25 10,
25,
10 5,
5 1,
1 00.55 and 00.11
20C
25, 10, 5, 1, 0.5 and 0.1
30 or 35C
CAIT
Asphalt Mixture Performance Tester (AMPT)
RUTGERS
Frequency (Hz)
25, 10, 5, 1, 0.5, 0.1 and 0.01
NY Mixture Master Curve
Plant Compacted PG 64
64--22
10,000,000
Dynam
mic Modulus (psi)
RAP %
1,000,000
40
30
20
0
Temperatures (o F)
Agg. Heating
gg
g
450
410
410
375
Silo Storage Time (hrs)
Mix Discharge
g
330
3
305
2.75
320
0.75
290
2.75
100,000
Callahan 64-22 40% RAP
Callahan 64-22 30% RAP
10,000
Callahan 64-22 20% RAP
Callahan 64-22 0% RAP
CAIT
1,000
1.0E-07
RUTGERS
1.0E-05
1.0E-03
1.0E-01
1.0E+01
1.0E+03
Loading Frequency (Hz)
1.0E+05
1.0E+07
Mixture Master Curve
Varying
y g % RAP

Generally, as the RAP content increased, the
stiffness of the mixtures increased.
increased This was true
for the 30% and 40% RAP mixtures.

However, the increase in the stiffness of the 30%
RAP mixture was not significant in comparison to
the control mixture
mixture.
Moreover,, the 20% RAP mixture had lower ||E*||
than the control mixture. This mixture was stored
in the silo for a much shorter time which
illustrates the significance of storage time on the
stiffness of the mixtures.
CAIT

RUTGERS
NY Mixture Master Curve
Same % RAP, Similar Production Parameters, Vary Binder Type
10,000,000
PG Grade (30% RAP)
Dynam
mic Moduluss (psi)
58‐28
64‐22
Temperatures (o F)
Agg. Heating
410
410
Mix Discharge
305
305
Silo Storage Time (hrs)
3.5
2.75
1,000,000
100,000
10,000
Callahan 58-28 30% RAP
Callahan 64-22 30% RAP
CAIT
1,000
1.0E-07
RUTGERS
1.0E-05
1.0E-03
1.0E-01
1.0E+01
1.0E+03
Loading Frequency (Hz)
1.0E+05
1.0E+07
NY Mixture Master Curve
Same % RAP,, Similar Production Parameters,, Varyy Binder Type
yp
10,000,000
PG Grade (40% RAP)
Dyn
namic Modulu
us (psi)
58 28
58‐28
64‐22
Temperatures (o F)
Agg. Heating
450
450
Mix Discharge
330
330
Silo Storage Time (hrs)
4
3
1,000,000
100,000
10,000
Callahan 58-28 40% RAP
Callahan 64-22 40% RAP
CAIT
1,000
1.0E-07
RUTGERS
1.0E-05
1.0E-03
1.0E-01
1.0E+01
1.0E+03
Loading Frequency (Hz)
1.0E+05
1.0E+07
Mixture Master Curve
Same % RAP
RAP, Similar Production Parameters
Parameters, Vary Binder Type

Data
D
t suggests
t the
th use off a softer
ft binder
bi d can
mitigate the stiffing due to the addition of
high percentages of RAP in the mixture
(First Figure).

Data also indicates that longer storage
times may nullify the possible benefit of the
softer asphalt binder (Second Figure).
CAIT
RUTGERS
NY Mixture Master Curve
0.75 hr silo storage time Plant vs. Laboratory Reheated
Dynamicc Modulus ((psi)
10,000,000
1,000,000
100,000
10,000
Callahan 64
64-22
22 20% RAP Plant Compacted
Callahan 64-22 20% RAP Reheated and Compacted
1,000
1.0E-07 1.0E-05 1.0E-03 1.0E-01 1.0E+01 1.0E+03 1.0E+05 1.0E+07
CAIT
RUTGERS
Loading Frequency (Hz)
NY Mixture Master Curve
3 hr silo storage time Plant vs. Laboratory Reheated
10,000,000
Dynam
mic Modulu
us (psi)
1,000,000
100,000
10,000
Callahan 64-22 40% RAP Plant Compacted
Callahan 64-22 40% RAP Reheated and Compacted
1,000
1.0E-07 1.0E-05 1.0E-03 1.0E-01 1.0E+01 1.0E+03 1.0E+05 1.0E+07
CAIT
RUTGERS
Loading Frequency (Hz)
NH Mixture Master Curve
1.25 hr silo storage time Plant vs. Laboratory Reheated
10,000,000
Dynamic Modulus ((psi)
1,000,000
100,000
10,000
Pike NH PG64-28 20% RAP - Plant Compacted
Pike NH PG64-28 20% RAP - Reheated and Compacted
1,000
1.0E-07
1.0E
07 1.0E
1.0E-05
05 1.0E
1.0E-03
03 1.0E
1.0E-01
01 1.0E+01 1.0E+03 1.0E+05 1.0E+07
CAIT
RUTGERS
Loading Frequency (Hz)
NH Mixture Master Curve
6 hr silo storage time Plant vs. Laboratory Reheated
10,000,000
Dynam
mic Modulus (psi)
1,000,000
100,000
10,000
Pike NH 64-28 0% RAP - Plant Compacted
p
Pike NH 64-28 0% RAP - Reheated and Compacted
1,000
1.0E-07 1.0E-05 1.0E-03 1.0E-01 1.0E+01 1.0E+03 1.0E+05 1.0E+07
CAIT
RUTGERS
Loading Frequency (Hz)
VT Mixture Master Curve
Plant vs. Laboratory Reheated
10,000,000
Pike VT PG52-34 20% RAP - Plant Compacted
Dyn
namic Modulu
us (psi)
Pike VT PG52-34
PG52 34 20% RAP - Reheated and Compacted
1,000,000
100,000
10,000
1,000
1.0E-07
CAIT
RUTGERS
1.0E-05
1.0E-03
1.0E-01
1.0E+01
1.0E+03
Loading Frequency (Hz)
1.0E+05
1.0E+07
VT Mixture Master Curve
Plant vs. Laboratory Reheated
10,000,000
Pike VT PG64-28 40% RAP - Plant Compacted
Dynamic Moduluss (psi)
Pike VT PG64-28 40% RAP - Reheated and Compacted
1,000,000
100,000
10,000
1,000
1.0E-07
CAIT
RUTGERS
1.0E-05
1.0E-03
1.0E-01
1.0E+01
1.0E+03
Loading Frequency (Hz)
1.0E+05
1.0E+07
General Stiffness Conclusions
 Increase in
RAP generally increased
stiffness, but not consistently –
apparent effect of silo storage time
 Reheated
mixture generally exhibited
higher stiffness than the mixtures
compacted at the plant. Some apparent
effect
ff
t
of
f
RAP
percentage
t
and/or
d/
silo
il
CAIT
RUTGERS
storage time
Plant Compacted vs Reheated
E* Ratio (Reeheated & Com
mpacted/Plant QC Lab Comp
pacted)
2.4
2.3
Low (4.4C)
2.2
Medium (20C)
2.1
High
g ((30 or 35C))
2
1.9
1.8
1.7
1.6
1.5
1.4
1.3
1.2
1.1
1
0.9
0.8
0.7
0.6
Pike - Pike - Call - Pike - Pike - Pike - Call - Pike - Pike - Pike - Call - Pike - Pike - Pike - Call - Pike VT VT NY NH VT VT NY NH VT VT NY NH VT VT NY NH
(52) (64) (64) (64) (52) (64) (64) (64) (52) (64) (64) (64) (52) (64) (64) (64)
CAIT
Virgin
RUTGERS
20% RAP
30% RAP
40% RAP
Importance of Sample Prep

Overall, when averaging the dynamic modulus at the
different test temperatures and loading frequencies, the
i
increase
i mixture
in
i t
modulus
d l ddue tto th
the addition
dditi off RAP
followed the following trend:
Plant QC Lab Compacted
- 0 to 20% RAP: 8% increase in mixture modulus
- 0 to 30% RAP: 29% increase in mixture modulus
- 0 to 40% RAP: 49% increase in mixture modulus
CAIT
RUTGERS
Loose Mix Reheated and Compacted
- 0 to 20% RAP: 17% increase in mixture modulus
- 0 to 30% RAP: 24% increase in mixture modulus
- 0 to 40% RAP:
RAP 27% iincrease in
i mixture
i
modulus
d l
Recovered
R
d Binder
Bi d Master
M t Curves
C
& Blending
g Analysis
y
CAIT
RUTGERS
Blending Analysis Methodology
Extract/Recover Binder
from Mixture
DSR Testing at
Multiple Temperatures
& Frequencies
BBR Testing at
Multiple Temperatures
& Times
Develop
De
elop Partial
Binder
Master Curves
CAIT
RUTGERS
Utilize Partial
Binder
Master Curve
& Hirsch Model to
Predict |E*|
Mixture Performance,
Workability
& Stiffness Testing
Degree of
Blending Comparison
|E*| Measured vs. |E*| Predicted
Stiffness
Dynamic Modulus |E*|
Binder Master Curves
Test Device
Intermediate Temperatures
Low Temperature
Dynamic Shear Rheometer
(DSR)
Bending Beam Rheometer
(BBR)
Temperature, C
10
22
34
46
58
70
-10, -16, -22, -28
Strain Level, %
0.1
1
1
5
10
10
n/a
Frequency (),
rad/sec
0.100, 0.159, 0.251, 0.398, 0.631,
1.000, 1.59, 2.51, 3.98, 6.31, 10.0,
1 9 225.1,
15.9,
1 39
39.8,
8 63
63.1,
1 100
n/a
Time, sec.
n/a
8, 15, 30, 60, 120, 240
CAIT
RUTGERS
Blending Analysis – NY 35C/10Hz
NY Mixtures - Temperature = 35°C & Frequency = 10Hz
Dynamic Modulus (ksi)
1000
100
10
1
PG64‐22 0%
RAP
CAIT
RUTGERS
PG64‐22
30% RAP
PG64‐22
40% RAP
Measured Plant E
Measured
Plant E*
Measured Reheated E*
PG58‐28
30% RAP
PG58‐28
40% RAP
Predicted Plant E
Predicted
Plant E*
Predicted Reheated E*
Blending Analysis – NY 20C/10Hz
Dynamic Mod
dulus (ksi)
10000
NY Mixtures - Temperature = 20°C & Frequency = 10Hz
1000
100
10
1
PG64‐22 0% RAP
CAIT
RUTGERS
PG64‐22
30% RAP
PG64‐22
40% RAP
Measured Plant E*
Measured Reheated E*
PG58‐28
30% RAP
PG58‐28
40% RAP
Predicted Plant E*
Predicted Reheated E*
Blending Analysis – NY 20C/1.0Hz
NY Mixtures - Temperature = 20°C & Frequency = 1Hz
Dyynamic Modulus (ksi)
10000
1000
100
10
1
PG64‐22 0%
RAP
CAIT
RUTGERS
PG64‐22
30% RAP
PG64‐22
40% RAP
Measured Plant E*
Measured Reheated E*
PG58‐28
30% RAP
PG58‐28
40% RAP
Predicted Plant E*
Predicted Reheated E*
Blending Analysis – NH 35C/1.0Hz
NH PG64-28 Mixtures - Temperature = 35°C & Frequency = 10Hz
Dynam
mic Modulus ((ksi)
1000
100
10
1
0% RAP
CAIT
RUTGERS
20% RAP
Measured Plant E*
Measured Reheated E*
30% RAP
40% RAP
Predicted Plant E*
Predicted Reheated E*
Blending Analysis – NH 20C/10Hz
NH PG64-28 Mixtures - Temperature = 20°C & Frequency = 10Hz
Dynam
mic Moduluss (ksi)
10,000
1,000
100
10
1
0% RAP
CAIT
RUTGERS
20% RAP
Measured Plant E
Measured
Plant E*
Measured Reheated E*
30% RAP
40% RAP
Predicted Plant E
Predicted
Plant E*
Predicted Reheated E*
Blending Analysis – NH 20C/1.0Hz
Dynamic Modulus (ksi)
1000
NH PG64-28 Mixtures - Temperature = 20°C & Frequency = 1Hz
100
10
1
0% RAP
CAIT
RUTGERS
20% RAP
Measured Plant E*
Measured
Plant E*
Measured Reheated E*
30% RAP
40% RAP
Predicted Plant E*
Predicted
Plant E*
Predicted Reheated E*
Blending Observations
 For the majority the test data indicated there was a
good
dd
degree off bl
blending
di ffor allll off th
the mixtures
i t
tested.
 The quality of blending may have been affected by
the plant discharge temperatures. In some cases
mixtures
i t
with
ith lower
l
discharge
di h
ttemperatures
t
showed less agreement between predicted and
measured |E
|E*||.
CAIT
RUTGERS
Additional Testing
g
CAIT
RUTGERS
Texas Overlay Test
- Test Temperature = 15ºC (59ºF)
- Test Termination at 11,200
200 cycles or 93%
Load reduction
- Testing in accordance with Tex-248-F
Diagram from: Zhou and Scullion “Overlay
Overlay Tester: A Rapid Performance Related Crack Resistance Test”
Test Report No.
No FHWA/TX-05/0-4467-2 (2005).
(2005)
CAIT
RUTGERS
Overlay Test Results – NY Mixtures
Mixture
NY
CAIT
RUTGERS
NMAS
% RAP
12.5 mm
0%
20%
30%
40%
30%
40%
Binder
Grade
PG 64-22
PG 58-28
Average
g OT
Cycles to Failure
111
121
90
22
70
13
Overlay Test Results – NH Mixtures
Mixture
NH
CAIT
RUTGERS
NMAS
% RAP
12.5 mm
0%
20%
30%
40%
Average OT
Binder Grade Cycles to
Failure
279
68
PG 64-28
113
50
Overlay Test Results – VT Mixtures
Mixture
VT
CAIT
RUTGERS
NMAS
% RAP
9.5 mm
0%
20%
30%
40%
0%
20%
30%
40%
Binder
Grade
PG 52-34
PG 64-28
Average OT
Cycles to
Failure
1,200
1,200
217
112
1,032
127
126
44
Overlay Test - Observations
Generally,
y, the cracking
g resistance as measured byy the OT
was reduced as the percentage of RAP in the mixture
increased.
 This
Thi data
d t agrees with
ith the
th stiffness
tiff
testing
t ti which
hi h iindicated
di t d
that the addition of RAP stiffened the resultant mixture.
Stiffer mixes generally are more susceptible to cracking at
moderate to high levels of deflection.
 The data indicated that the use of the softer grade binder
for the New York mixtures did not have the desired effect of
improving the cracking resistance of the mixtures.
 The softer binder improved
p
the cracking
g characteristics of
the Vermont RAP mixtures
CAIT

RUTGERS
Phase I Conclusions

Plant production and silo storage practices, as well
as how the material is handled prior to specimen
fabrication (i.e. – reheating loose mix or not) will
have an impact on the mixture performance.

In general, discharge temperatures and silo
storage
g factors were found to highly
g y influence
mixture stiffness and cracking properties.

Production parameters (discharge temperature)
may have an impact on the relative degree of
blending between the RAP and virgin binders.
CAIT
RUTGERS
Phase I Conclusions

The data indicated that the reheated mixtures
exhibited significantly higher stiffness than the
mixtures
i t
compacted
t d att the
th plant.
l t

Sensitivity of mixture stiffness to increased RAP
content decreased when reheated as compared to
plant compacted specimens.

Of the 12.5 mm mixtures, only the NY 30% RAP
mixture failed in the HWTD. The discharge
temperature for this mixture was lower (305 F) than
all the mixtures that passed the moisture
susceptibility test (>320 F)
CAIT
RUTGERS
Phase I Conclusions

The Overlay Tester results showed that the
cracking resistance was reduced as the
percentage of RAP in the mixture increased.

Use of the softer grade binder for the NY mixtures
did not have the desired effect of improving the
cracking resistance of the mixtures.
mixtures However
However, the
softer binder improved the cracking characteristic
of the VT mixtures.
CAIT
RUTGERS
Research - Phase II

Additional mixtures evaluated based on
preliminary results obtained during Phase I
 NH
Mixtures with associated test sections
– PG 58-28 at 0%, 15%, 25% RAP
– PG 52
52-34
34 att 25%
25%, 30%
30%, 40% RAP
 Higher
 Silo
PG grade mixtures (VA)
storage study
– Virgin & 30% RAP mixtures
– Sample at 0, 2, 4, 8, 12 hours

Additional nano-indentation
nano indentation testing
CAIT
RUTGERS
Thank you for your time!
Thomas Bennert, Rutgers University
bennert@rci rutgers edu
bennert@rci.rutgers.edu
CAIT
RUTGERS