$18 Million Benefits of $18 Million Benefits of Using Ground Tire Using Ground Tire Rubber In Asphalt:Rubber In Asphalt:

Eleven Years of Eleven Years of SuccessSuccess

George Way, P.E.George Way, P.E.

Arizona DOTArizona DOT

Flagstaff I-40Flagstaff I-40

Elev. 2133 MetersElev. 2133 Meters

254 cm of snow254 cm of snow

Lowest Temp. -31 CLowest Temp. -31 C

I-40 TrafficI-40 Traffic

20,000 VPD20,000 VPD

35% Trucks35% Trucks

2.3 million 2.3 million ESAL’s/YearESAL’s/Year

Riordan ProjectRiordan Project

Built 1985Built 1985

25 cm HMA25 cm HMA

15 cm Perm HMA15 cm Perm HMA

15 cm Drainable AB15 cm Drainable AB

RIORDAN CROSS SECTIONRIORDAN CROSS SECTION

28 cm AC28 cm AC

15 cm BTB15 cm BTB

10 cm AB10 cm AB

Eng. FabricEng. Fabric

Sub GradeSub Grade

Built 1969Built 1969

20 cm PCCP20 cm PCCP

18 cm CTB18 cm CTB

Clay/Cinder SubgradeClay/Cinder Subgrade

I-40 PavementI-40 Pavement

Badly CrackedBadly Cracked

Rough RideRough Ride

High MaintenanceHigh Maintenance

Flagstaff OverlayFlagstaff Overlay

Crack & SeatCrack & Seat

7.5 cm HMA7.5 cm HMA

5 cm AR-HMA5 cm AR-HMA

1.25 cm AR-OGFC1.25 cm AR-OGFC

FLAGSTAFF CROSS SECTIONFLAGSTAFF CROSS SECTION

1.25 cm AR-OGFC1.25 cm AR-OGFC

5 cm AR-AC5 cm AR-AC

7.5 cm AC7.5 cm AC

PCCP Crack & SeatPCCP Crack & Seat

Sub GradeSub Grade

Arizona D.O.T , Materials GroupAR-AC & AR-ACFC GRADATION CHART

0

10

20

30

40

50

60

70

80

90

100

Sieve Sizes to .45 Power

% P

ass

ing

AR-AC

AR-ACFC

#200 #100 #50 #40 #30 #16 #10 #8 # 4 1/4” 3/8” 1/2” 3/4”

Asphalt RubberAsphalt Rubber

80 % Asphalt80 % Asphalt

20 % Ground Tire 20 % Ground Tire RubberRubber

Percent BinderPercent Binder

4.6% HMA/AC-204.6% HMA/AC-20

6.6% AR-HMA6.6% AR-HMA

9.0% AR-OGFC9.0% AR-OGFC

Metric Ton of MixMetric Ton of Mix

Mix Type K gs ofAsphalt

K gs ofRubber

HMA 42 0

AR-HMA 48 12

AR-OGFC 66 16

HMA-Asphalt HMA-Asphalt BinderBinder

AC-20AC-20

PG 64-16PG 64-16

Asphalt Rubber Asphalt Rubber BinderBinder

AC-10AC-10

PG 58-22PG 58-22

SHRP SPS-6

National Overlay Study

Focus on Thickness

10 cm & 20 cm HMA Overlay

SHRP SPS-6SHRP SPS-6Overlay PCCPOverlay PCCP

20 cm HMA 20 cm HMA

10 cm HMA10 cm HMA

5 cm AR-HMA/5 cm 5 cm AR-HMA/5 cm HMAHMA

CrackingCracking

• Flagstaff Flagstaff ARAR

• RiordanRiordan

0

2

4

6

8

10

12

1st

Yea

r

4th

Yea

r

7th

Yea

r

9th

Yea

r

FlagstaffRiordan

Cracking in MetersCracking in Meters

050

100150200250300350

1stYear

4thYear

7thYear

9thYear

AR-HMA8"-HMA4"-HMA

Percent CrackingPercent Cracking

0

2

4

6

8

10

12

1styear

4thyear

7thyear

9thyear

AR-HMAAR-SHRP8"-HMA4"-HMARiordan

Benefits of ARBenefits of AR

$18 million savings$18 million savings

Four Years Less Four Years Less Construction TimeConstruction Time

ImplementationImplementation

Over 2,500 miles of AR Over 2,500 miles of AR projects built since projects built since

19901990