Asphalt Specification Changes July 2005 Contractor Asphalt Training Rich Hewitt, PE District Bituminous Engineer District Five Materials & Research
Asphalt Specification Changes July 2005 What are we going to talk about? What are we going to talk about? Background & General Information Background & General Information Specifics on 334 Changes…a bunch! Specifics on 334 Changes…a bunch! Specifics on 337 Changes…a few! Specifics on 337 Changes…a few! Specifics on 234 Changes…one slide! Specifics on 234 Changes…one slide! Questions & Discussion Questions & Discussion
Asphalt Specification Changes July 2005 CQC Asphalt Specification Task Team CQC Asphalt Specification Task Team Industry, FHWA, FDOT Industry, FHWA, FDOT Fall 2004 Fall 2004 Statistical evaluation of data Statistical evaluation of data Review significant changes to… Review significant changes to… 334 Superpave Asphalt Concrete 334 Superpave Asphalt Concrete 337 Asphalt Concrete Friction Courses 337 Asphalt Concrete Friction Courses 234 Superpave Asphalt Base 234 Superpave Asphalt Base
Asphalt Specification Changes Section 334 General reorganization: General reorganization: Description Description Materials Materials General Composition of Mixture General Composition of Mixture Contractor Process Control Contractor Process Control Acceptance of the Mixture Acceptance of the Mixture Comparison Testing Comparison Testing Method of Measurement Method of Measurement Basis of Payment Basis of Payment
Asphalt Specification Changes Section Acceptance of the Mixture Acceptance of the Mixture General General Lot Sizes Lot Sizes Initial Production Requirements Initial Production Requirements Quality Control Sampling and Testing Quality Control Sampling and Testing Verification Testing Verification Testing Resolution System Resolution System Independent Sample Verification Testing Independent Sample Verification Testing Surface Tolerance Surface Tolerance Minimum Acceptable Quality Levels Minimum Acceptable Quality Levels
Asphalt Specification Changes Section Thickness Thickness Specify thickness instead of spread rate Specify thickness instead of spread rate Old: 200 lbs/yd 2 Old: 200 lbs/yd 2 New: 2 inches New: 2 inches Control based on spread rate Control based on spread rate Convert thickness to spread rate: Convert thickness to spread rate: Spread rate (lbs/yd 2 ) = t x G mm x 43.3 Spread rate (lbs/yd 2 ) = t x G mm x 43.3 Plan quantities based on G mm of Plan quantities based on G mm of Approximately 110 lbs/yd 2 – granite mix Approximately 110 lbs/yd 2 – granite mix
Asphalt Specification Changes Section Thickness Thickness Fine Mixes (Nearest ½ inch) Fine Mixes (Nearest ½ inch) Type SP-9.51 – 1½ inches Type SP-9.51 – 1½ inches Type SP-12.51½ - 2½ inches Type SP-12.51½ - 2½ inches Type SP inches Type SP inches Permits two layers of SP-9.5 (fine) Permits two layers of SP-9.5 (fine) Stacking Stacking Can’t use SP-9.5 (fine) on Traffic Level D & E Can’t use SP-9.5 (fine) on Traffic Level D & E
Asphalt Specification Changes Section Thickness Thickness Coarse Mixes (Nearest ½ inch) Coarse Mixes (Nearest ½ inch) Type SP-9.51½ - 2 inches Type SP-9.51½ - 2 inches Type SP inches Type SP inches Type SP ½ inches Type SP ½ inches
Asphalt Specification Changes Section Superpave Asphalt Binder: Superpave Asphalt Binder: PG – Standard Binder Grade PG – Standard Binder Grade Traffic Level D – PG top structural layer Traffic Level D – PG top structural layer PG is polymer modified PG is polymer modified Traffic Level E – PG top two structural layers Traffic Level E – PG top two structural layers Mix Design: Mix Design: 3 mix designs/NMAS/traffic level/binder grade/contract year 3 mix designs/NMAS/traffic level/binder grade/contract year Coarse and fine allowed for all Traffic Levels Coarse and fine allowed for all Traffic Levels
Asphalt Specification Changes Section Process Control Process Control Address in QC Plan how PC failures will be handled Address in QC Plan how PC failures will be handled Basically need to address problem, then resample Basically need to address problem, then resample Second failure stop production, contact Engineer Second failure stop production, contact Engineer Acceptance Testing Exceptions: Acceptance Testing Exceptions: Less than 500 tons of any mix type, visual inspection Less than 500 tons of any mix type, visual inspection Engineer may require PC tests or IV tests Engineer may require PC tests or IV tests
Asphalt Specification Changes Section Lot Sizes Lot Sizes If a Lot is terminated on QC failure, Lot sizes go to 2000 tons If a Lot is terminated on QC failure, Lot sizes go to 2000 tons Partial Lots will not be redefined Partial Lots will not be redefined Individual Test Tolerances for Quality Control Testing: Individual Test Tolerances for Quality Control Testing: Revised Master Production Range Revised Master Production Range
Asphalt Specification Changes Section 334 Table Master Production Range Characteristic Tolerance (1) Asphalt Binder Content ( percent) Target ± 0.55 Passing No. 8 [2.36 mm] Sieve ( percent) Target ± 5.50 Passing No. 200 [75 µm] Sieve ( percent) Target ± 1.50 Air Voids ( percent) Coarse Graded 2.00 – 6.00 wider Air Voids ( percent) Fine Graded 2.30 – 6.00 wider Density, percent G mm (2) Coarse Graded (minimum) Coarse Graded (minimum)93.00 Fine Graded (minimum) new (1) Tolerances for sample size of n = 1 from the verified mix design (2) Based on an average of 5 randomly located cores
Asphalt Specification Changes Section Individual Test Tolerances for Quality Control Testing: Individual Test Tolerances for Quality Control Testing: Added single density value < 91.00% Added single density value < 91.00% Coarse mixes Coarse mixes Single low density value – correct problem Single low density value – correct problem Two in same sublot - stop Two in same sublot - stop Any Lot terminated on QC failure is limited to a maximum pay factor of 1.00 per characteristic Any Lot terminated on QC failure is limited to a maximum pay factor of 1.00 per characteristic Verification Testing: Verification Testing: Single non-comparison → Resolution Single non-comparison → Resolution
Asphalt Specification Changes Section Resolution Determination: Resolution Determination: No additional time granted No additional time granted Defective Material: Defective Material: “Cleaned up” “Cleaned up” Better describes actual process Better describes actual process Allows delineation testing Allows delineation testing
Asphalt Specification Changes Section Pay Factors: Pay Factors: Modified Small Quantity Pay Table Modified Small Quantity Pay Table Modified PWL Spec Limits Modified PWL Spec Limits
Table Specification Limits Quality CharacteristicSpecification Limits Passing No. 8 [2.36 mm] sieve ( percent)Target ± 3.1 Passing No. 200 [75 m] sieve ( percent) Target ± 1.0 Asphalt Content ( percent)Target ± 0.40 Air Voids – Coarse Mixes ( percent)4.00 ± 1.40 Air Voids – Fine Mixes ( percent) tighter 4.00 ± 1.20 tighter Density – Coarse Mixes ( percent of G mm ):94.50 ± 1.30 Density – Fine Mixes ( percent of G mm ): , wider (1) wider Note (1): If the Engineer (or Contract Documents) limits compaction to the static mode only, the specification limits are as follows: , No additional compensation, cost or time, shall be made.
Asphalt Specification Changes Section 337 Asphalt Concrete Friction Courses Asphalt Binder: Asphalt Binder: Use PG when called for in Contract, otherwise ARB Use PG when called for in Contract, otherwise ARB Individual Test Tolerances for FC-5 Production: Individual Test Tolerances for FC-5 Production: Single binder content out = stop Single binder content out = stop Two out on gradation = stop Two out on gradation = stop Address IAW “Defective Material” Address IAW “Defective Material” Note: no longer exists, was intended.
Asphalt Specification Changes Section Thickness of Friction Courses Thickness of Friction Courses FC-9.5 & FC-12.5: use FC-9.5 & FC-12.5: use Spread rate (lbs/yd 2 ) = t x G mm x 43.3 Spread rate (lbs/yd 2 ) = t x G mm x 43.3 FC-5: FC-5: Spread rate (lbs/yd 2 ) = t x G sb x 40.5 Spread rate (lbs/yd 2 ) = t x G sb x 40.5 G sb = combined aggregate bulk specific gravity of the verified mix design G sb = combined aggregate bulk specific gravity of the verified mix design Plan quantities based on G sb of Plan quantities based on G sb of Spread rate of 80 lbs/yd 2 Spread rate of 80 lbs/yd Hydrated Lime Pretreatment: Hydrated Lime Pretreatment: Allow lime pretreated aggregate Allow lime pretreated aggregate 45-day window for use after pretreatment 45-day window for use after pretreatment Spec addresses QC and certification requirements for blending operations Spec addresses QC and certification requirements for blending operations
Asphalt Specification Changes Section 234 Superpave Asphalt Base Thickness Requirements Thickness Requirements. Convert thickness to spread rate: Convert thickness to spread rate: Spread rate (lbs/yd 2 ) = t x G mm x 43.3 Spread rate (lbs/yd 2 ) = t x G mm x 43.3
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