Download - Asphalt Rubber Asphalt Concrete Friction Course Overlay as a Pavement Preservation Strategy
Asphalt Rubber Asphalt Concrete Friction Course Overlay as a
Pavement Preservation Strategy
K. Kaloush, K. Biligiri, M. Rodezno, M. BelsheArizona State University,
G. Way and D. Carlson, Rubber Pavement Association, Arizona, USA.
J. Sousa, Consulpav International, Inc. USA - Portugal
SIXTH MEXICAN ASPHALT CONGRESSCancun, Mexico, August 24th to 28th, 2009
Presentation Outline• Objectives of Study• Background on Asphalt Rubber• AR Pavement Preservation Strategy
- Performance / Durability
- Highway Noise
- Thermal Gradient / Urban Climate Interaction
- Friction / Safety and Ride Quality / Comfort
- Tire Wear Emissions / Air Quality
- Cost and Energy Consideration
• Summary and Conclusions
Objective
Evaluation of AR-ACFC benefits as a pavement preservation strategy in terms of laboratory material characterization tests and field performance evaluation including: highway noise reduction, mitigation of daily thermal variances in PCC pavements, improved skid resistance, reduced roughness, and reduction of emission rates of tire wear.
ASTM D8Standard Definitions of Terms Relating to Materials for Standard Definitions of Terms Relating to Materials for
Roads and PavementsRoads and Pavements
Asphalt Rubber– a blend of asphalt cement, reclaimed tire rubber and certain additives in which the rubber component is at least 15% by weight of the total blend and has reacted in the hot asphalt cement sufficiently to cause swelling of the rubber particles.
Existing or new HMA Base Mix
AR Bitumen 6.8- 8%Air Voids 7 - 10%
AR Bitumen Content 8.8 - 10%Air Voids 18 - 20%
Typical HMA Cross Section
ARFC
13 mm
ARAC
50 mm ARAC
OpenGap / SMA
Dense
Base Asphalts for AR Use
Type 1: Hot Climate PG 64-16 (Pen 60/70)
Type 2: Moderate Climate PG 58-22 (Pen 80/100)
Type 3: Cold Climate PG 52-28 (Pen 200/300)
Is AR a Good Pavement Preservation Strategy?
1. Performance / Durability
2. Highway Noise
3. Thermal Gradient / Urban Climate Interaction
4. Friction / Safety
5. Ride Quality / Comfort
6. Tire Wear Emissions / Air Quality
7. Cost and Energy Consideration
• Binder Tests• Triaxial Shear Strength• Dynamic Modulus E*• Permanent Deformation FN / FT• Fatigue• IDT Creep and Strength
1- Performance / Durability
Viscosity-Temperature Relationships
0
0.2
0.4
0.6
0.8
1
1.2
2.7 2.75 2.8 2.85 2.9 2.95
Vis
cosi
ty (L
og L
og c
P)
ADOT Virgin PG 76-16I-17 AR PG 58-22I-17 AR PG 64-16I-40 AR PG 58-22
Alberta AR Pen 150-200
Temperature Rankine (R)
Dynamic Complex Modulus E* AASHTO TP 62-03
100
1,000
10,000
100,000
-8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8
Log Reduced Time (sec)
E*
(Mpa
)
AR-ACFC-Unconfined Confined 69 Kpa
Confined-138 Kpa Confined-207 Kpa
54.4°C0.1 Hz
2- Tire / Pavement Noise (dB) for Arizona I-10 Test Sections
Field Noise Validation Studies
102.84
99.94
104.68
101.56102.17
99.8
101.0
100.6
99.8
98.9
96
97
98
99
100
101
102
103
104
105
106
AR-ACFC ACFC P-ACFC PEM SMA
Tir
e / P
avem
ent
Nois
e (d
B)
Dynatest 2008 at 100 Km/h Scofield-Donovan 2002 at 100 Km/h
I-10 TEST SECTIONSAR-ACFC ¾”
SMA ¾”P-ACFC ¾”
PEM 1 ¼” ACFC ¾”Field Noise
Validation Studies
3- Field Investigation of PCC Thermal Behavior
• Temperature Gradients induce damaging Curling Stresses
Courtesy AZ511.com
Thermal Gradient Test Site
Thermal Gradients Effect• Observed benefits of
porosity and lower thermal mass of the ARFC layer.
• Thermal Blanket Effect of ARFC reduces PCC Curling Stresses (8-25%)
Urban Heat Island
4- Friction / SafetyAverage Friction Value
LANE PCCP AR-ACFC
I010EHOV 0.54 0.66 I010ELN1 0.60 0.61 I010ELN2 0.49 0.61 I010ELN3 0.47 0.60 I010ELN4 0.47 0.54
I010WHOV 0.51 0.58 I010WLN1 0.64 0.57 I010WLN2 0.50 0.59 I010WLN3 0.44 0.59 I010WLN4 0.42 0.58
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
50 250 450 650 850 1050 1250 1450 1650 1850 2050 2250 2450 2650
Fri
ctio
n V
alu
e (M
u)
Friction average every 50 feet
Friction Test-Deck Park Tunnel I010 East HOV Lane @ 60 mph Comparison PCCP to AR-ACFC
PCCP
AR-ACFC
Profilometer Test-Deck Park Tunnel I010 East HOV Comparison PCCP to AR
102030405060708090
100110120130140150160170
100
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
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2100
2200
2300
2400
2500
2600
2700
Distance every 100ft
IRI(
IN/M
I)
P CCP
A R
5- Ride Quality / RoughnessIRI (in/mi)
LANE PCCP AR-ACFC
I010EHOV 96.34 43.57 I010ELN1 123.20 59.03 I010ELN2 104.29 48.81 I010ELN3 111.87 47.80 I010ELN4 115.30 52.91
I010WHOV 85.44 32.51 I010WLN1 87.94 37.79 I010WLN2 85.40 46.92 I010WLN3 96.83 46.11 I010WLN4 97.75 36.81
6- Air Quality• Rare opportunity to sample tire wear emissions at the
tunnel before and after the AR-ACFC overlay.
Deck Park Tunnel, I-10 Phoenix, AZ
Based on Tire Wear TracersTire Wear Emission Rates
Emission rates calculated per kilometer driven (g/km).Tire wear
emission rate based on
Experiment 1 (PCC road surface)
Experiment 2 (AR-ACFC road surface)
Compound # 3 354 ± 71 177 ± 35 Compound # 4 172 ± 34 120 ± 24
May 2004 and June 2005
Process kJ/kg
Tire Shedding -1744
Shred Transportation -1744
Granulation -3586
CRM Transportation -1744
Steel Recovery 1900
Asphalt Saved 209,325 to 465,168
Aggregate Saved 107,860
Gain / Loss 310,267 to 566,109
½ Thickness Design Criteria
7- Energy Consideration
Positive Impact on CO2 Emissions
Cost Benefits•Longer Service Life•Reduced cracking and maintenance.•Reduced thickness.
0
100
200
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500
600
700
800
900
1000
1100
1200
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
Year
Ma
inte
na
nc
e C
os
t $
/la
ne
-Km
Overlays / Inlays
AR-ACFC
Conclusions• AR-ACFC is a System Preservation Design Strategy:
– Performance / Durability √
– Safety √– Ride Quality √
– Quality of Life Issues √• Highway Noise
• Air Quality
• Urban Heat Island
– Energy Savings and Cost Effective √
Arizona - USAThank You