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R eclaimed A sphalt P avement in Arizona - Application and Verification. October 3, 2008 Arizona Association of County Engineers. Outline. Introduction Project Overview Existing Pavement Condition Construction and Production Operations Granite/ADOT Test Results Summary. Outline.
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Reclaimed Asphalt Pavement in Arizona - Application and Verification October 3, 2008 Arizona Association of County Engineers
Outline • Introduction • Project Overview • Existing Pavement Condition • Construction and Production Operations • Granite/ADOT Test Results • Summary
Outline • Introduction • Project Overview • Existing Pavement Condition • Construction and Production Operations • Granite/ADOT Test Results • Summary
Changing Market Conditions = Renewed Interest in Recycling • Price escalation for construction/rehabilitation and maintenance • Asphalt binder shortages • Polymer shortages • Environmental concerns • Energy concerns • Funding limitations
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
Value of Recycling – Percent Savings Relative to Conventional Materials – Initial Construction* *equivalent square yardsNote: Similar advantages found with Life Cycle Cost
PCI Over Time* *Projects constructed in Arizona
Outline • Introduction • Project Overview • Existing Pavement Condition • Construction and Production Operations • Granite/ADOT Test Results • Summary
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 HMA • 6% 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
Outline • Introduction • Project Overview • Existing Pavement Condition • Construction and Production Operations • Granite/ADOT Test Results • Summary
Alligator Cracking Moderate severity alligator cracking Existing pavement prior to rehabilitation
Transverse Cracking Slight to moderate severity transverse cracking Existing pavement prior to rehabilitation
Block Cracking Block cracking Existing pavement prior to rehabilitation Maybe considered combination of longitudinal and transverse cracking
Outline • Introduction • Project Overview • Existing Pavement Condition • Construction and Production Operations • Granite/ADOT Test Results • Summary
Hot Plant Feeders 5 Virgin Aggregate Bins 2 RAP Bins
Hot Plant Cement Silo and Pugmill Virgin Aggregate Scalping Screen
Hot Plant Counter Flow Drum Mixer RAP Conveyor
Paving and Inspection HMA Paving Density Testing
Rolling Operations Echelon Breakdown Rolling Finish Rolling
Outline • Introduction • Project Overview • Existing Pavement Condition • Construction and Production Operations • Granite/ADOT Test Results • Summary
Granite Test Results – RAP* *Test results based on ignition oven**Standard Deviation – measure of variability
Granite Test Results – RAP* *Test results based on solvent extraction**Standard Deviation – measure of variability
Granite/ADOT Test Results - Gradation • Gradation of aggregate extracted from field mixed samples *Standard Deviation – measure of variability
Granite/ADOT Test Results - Volumetrics • Volumetric properties of field mixed/lab compacted samples *Standard Deviation – measure of variability
Outline • Introduction • Project Overview • Existing Pavement Condition • Construction and Production Operations • Granite/ADOT Test Results • Summary
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