7/31/2019 Optimizing Asphalt Mix Designs
1/16
OPTIMIZING ASPHALTMIX DESIGNS
MIX DEVELOPMENT, AGENCY APPROVAL, MATERIALMANAGEMENT, FIELD ADJUSTMENTS
Rocky Mountain Asphalt Conference and Equipment ShowFebruary 25, 2010
1
7/31/2019 Optimizing Asphalt Mix Designs
2/16
DEFINE OPTIMIZING
Whos Perspective
Producer
Paving Contractor
General Contractor
Owner
2
7/31/2019 Optimizing Asphalt Mix Designs
3/16
MIX DEVELOPMENT
Project Specifications
Asphalt Binder Selection
Recycled Materials Recycled Asphalt Pavement (RAP)
Recycled Asphalt Shingles (RAS)
3
7/31/2019 Optimizing Asphalt Mix Designs
4/16
MIX DEVELOPMENT
Aggregate Source / Characteristics
Aggregate Production Stationary or Mobile Plant
Hot Mix Asphalt Production Stationary or Mobile Plant
4
7/31/2019 Optimizing Asphalt Mix Designs
5/16
5
Design Considerations
7/31/2019 Optimizing Asphalt Mix Designs
6/16
5
Design Considerations
Quality
7/31/2019 Optimizing Asphalt Mix Designs
7/16
5
Design Considerations
Availability
Quality
7/31/2019 Optimizing Asphalt Mix Designs
8/16
5
Design Considerations
Availability
Quality
Balance
7/31/2019 Optimizing Asphalt Mix Designs
9/16
5
Design Considerations
Availability
Quality
Balance
7/31/2019 Optimizing Asphalt Mix Designs
10/16
5
Design Considerations
Availability
Quality
Economics
Balance
7/31/2019 Optimizing Asphalt Mix Designs
11/16
AGENCY APPROVAL Conformance to contract requirements
Selection of JMF Durability considerations
Appropriate binder content for location
Strength (stability) considerations
Avoid fat side of VMA
6
7/31/2019 Optimizing Asphalt Mix Designs
12/16
MATERIAL MANAGEMENT
Aggregate Quality Control Tests
Gradation, Specific Gravity, Angularity
Frequency
Stockpiling / Handling
Recycled Product(s) Quality Control Tests
Asphalt Binder Content, Gradation, Binder Grade
Frequency
Stockpiling / Handling
7
7/31/2019 Optimizing Asphalt Mix Designs
13/16
MATERIAL MANAGEMENT
Asphalt Binder Tests
Binder Grading AASHTO M320, PG 64-28 add Toughness andTenacity
Frequency
Storage and Handling
Hot Mix Asphalt Production Control Tests
Gradation, Asphalt Binder Content, Theoretical MaximumSpecific Gravity, % Voids, Calculate % Voids in MineralAggregate
Frequency
8
7/31/2019 Optimizing Asphalt Mix Designs
14/16
FIELD ADJUSTMENTS
Typical Production Results versus Laboratory DesignData for the Same Gradation and Asphalt Bindercontent:
Increased Bulk Specific Gravity of Mixture
Lower % Voids in Mix
Lower Calculated % VMA
9
7/31/2019 Optimizing Asphalt Mix Designs
15/16
FIELD ADJUSTMENTS
Adjusting to Meet Volumetric Targets DuringProduction
Acceptance Criteria Gradation Acceptance or VoidsAcceptance?
Analyze Trends
Binder content in comparison with Rice Binder content in comparison with air voids
10
7/31/2019 Optimizing Asphalt Mix Designs
16/16
FIELD ADJUSTMENTS
Gradation Acceptance / Voids Acceptance
Reduce Asphalt Binder Content if %VMA is OK
Change Gradation For a mix above the Maximum Density Line target the
Fine Side of the Targets without increasing -#200
Reject Baghouse Fines if Necessary to Reduce -#200
Request Target Changes to Asphalt Binder Content andGradation / Request Target Change to Asphalt BinderContent
11