1 Reclaimed Asphalt Pavement in Arizona - Application and Verification October 3, 2008 Arizona...
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Transcript of 1 Reclaimed Asphalt Pavement in Arizona - Application and Verification October 3, 2008 Arizona...
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RReclaimed eclaimed AAsphalt sphalt PPavement in avement in Arizona - Application and Arizona - Application and VerificationVerification
October 3, 2008
Arizona Association of County Engineers
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Outline
IntroductionProject OverviewExisting Pavement ConditionConstruction and Production OperationsGranite/ADOT Test ResultsSummary
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Outline
IntroductionProject OverviewExisting Pavement ConditionConstruction and Production OperationsGranite/ADOT Test ResultsSummary
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Price escalation for construction/rehabilitation and maintenance
Asphalt binder shortages Polymer shortages Environmental concerns Energy concerns Funding limitations
Changing Market Conditions = Renewed Interest in Recycling
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States Allowance of RAP
75-percent of States allow at least 10-percent RAP in surface course mixes
More States allow higher percentages in lower lifts
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15% RAP in HMA 25% RAP in HMA
Energy, BTU 5 8
AC Consumed, tons 12 19
Aggregate Consumed, tons 6 10
CO2 (lb) 7 12
CO (lb) 8 13
NOx (lb) 5 9
SOx (lb) 9 16
PM-10 (lb) 6 10
Value of Recycling – Percent Savings Relative to Conventional Materials – Initial
Construction*
*equivalent square yardsNote: Similar advantages found with Life Cycle Cost
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PCI Over Time*
*Projects constructed in Arizona
0
10
20
30
40
50
60
70
80
90
100
0 1 2 3 4 5 6 7 8 9 10
Time (Years)
PC
I
Conventional HMA
Recycled HMA
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Outline
IntroductionProject OverviewExisting Pavement ConditionConstruction and Production OperationsGranite/ADOT Test ResultsSummary
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Scope of Work Partial depth removal of existing asphalt concrete Placement of dense grade asphalt concrete Placement of AR-ACFC Miscellaneous other work Granite’s Proposal
Use RAP in base course HMA6% coarse RAP (3/4-in x 3/8-in)9% fine RAP (3/8-in minus)
Note: RAP currently used as shoulder backing and aggregate base on ADOT projects
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Outline
IntroductionProject OverviewExisting Pavement ConditionConstruction and Production OperationsGranite/ADOT Test ResultsSummary
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Alligator Cracking
Moderate severity alligator cracking Existing pavement prior to rehabilitation
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Transverse Cracking
Slight to moderate severity transverse cracking Existing pavement prior to rehabilitation
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Block Cracking
Block cracking
Existing pavement prior to rehabilitation
Maybe considered combination of longitudinal and transverse cracking
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Outline
IntroductionProject OverviewExisting Pavement ConditionConstruction and Production OperationsGranite/ADOT Test ResultsSummary
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Outline
IntroductionProject OverviewExisting Pavement ConditionConstruction and Production OperationsGranite/ADOT Test ResultsSummary
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Granite Test Results – RAP*
Testing Lab
RAP Source
Stat3/8-in
Sieve, % Passing
No. 8 Sieve, % Passing
No. 40 Sieve, % Passing
No. 200, % Passing
Asphalt Binder
Content, %DWA
Granite - Arizona
CoarseNo. 10 10 10 10 10
Std. Dev.** 3.5 2.0 1.1 0.38 0.53
FineNo. 11 11 11 11 11
Std. Dev. 0.0 1.9 1.6 1.17 1.09
Granley Std. Dev. 2.81 0.94 0.28
Rep. Range Std. Dev. 2.0 – 4.5 2.0 – 3.5 0.5 – 1.5 0.15 – 0.45
Rep. Value Std. Dev. 3.30 2.80 0.90 0.30
*Test results based on ignition oven**Standard Deviation – measure of variability
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Granite Test Results – RAP*
Testing Lab
RAP Source
Stat3/8-in
Sieve, % Passing
No. 8 Sieve, % Passing
No. 40 Sieve, % Passing
No. 200, % Passing
Asphalt Binder
Content, %DWA
Granite - Arizona
CoarseNo. 5 5 5 5 5
Std. Dev.** 5.3 3.2 1.5 0.60 0.42
FineNo. 7 7 7 7 7
Std. Dev. 0.0 1.9 1.1 0.70 0.22
Granley Std. Dev. 2.81 0.94 0.28
Rep. Range Std. Dev. 2.0 – 4.5 2.0 – 3.5 0.5 – 1.5 0.15 – 0.45
Rep. Value Std. Dev. 3.30 2.80 0.90 0.30
*Test results based on solvent extraction**Standard Deviation – measure of variability
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Granite/ADOT Test Results - Gradation
*Standard Deviation – measure of variability
Gradation of aggregate extracted from field mixed samples
Standard Deviation of Percent Passing Sieve, %
3/8-in No. 8 No. 40 No. 200
Granite 2.95 2.56 1.18 0.57
ADOT 3.22 2.14 0.88 0.46
Granite & ADOT 3.10 2.35 1.04 0.51
Granley 2.81 0.94
NCHRP 455
Rep. Range 2.0 – 4.5 2.0 – 3.5 0.5 – 1.5
Rep. Value 3.3 2.8 0.9
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Granite/ADOT Test Results - Volumetrics
*Standard Deviation – measure of variability
Volumetric properties of field mixed/lab compacted samples
Bulk Density,
lb/ft3
Rice Density,
lb/ft3
Air Voids, %
Asphalt Binder
Content, %
Granite 0.95 0.58 0.81 0.29
ADOT 0.80 0.49 0.67 0.21
Granite & ADOT 0.88 0.53 0.74 0.25
Granley 0.28
NCHRP 455
Rep. Range 0.3 – 1.2 0.15 – 0.45
Rep. Value 0.7 0.3
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Outline
IntroductionProject OverviewExisting Pavement ConditionConstruction and Production OperationsGranite/ADOT Test ResultsSummary
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Recycling Benefits
Conservation Materials (aggregate and asphalt binder)
Energy (burner fuel, trucking, etc.)
Preservation of environment Landfill
Green house gases (global warming)
Sustainability
Economics Reduce first and life cycle cost
Complete reconstruction vs. alternative methods
Increased contractor competition