1

Overview CQC Asphalt Specifications

In a Nutshell….

Payment based on Contractor’s Quality Control tests.

FDOT runs verification tests at a lesser frequency.

Payment is based on roadway density, air voids, asphalt content and gradation. Uses Percent Within Limits (PWL) statistical specs. Separate Master Production Range to catch

outliers. Began with July 2002 workbook.

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Basics

Standard Lot size: 4,000 tons for dense mix or 2000 tons for

OGFC. Four sublots per Lot. Plant Lot & Roadway Lot same. Engineer establishes sampling points.

Random basis. Use Excel spreadsheet. Directs Contractor when to sample.

Contractor does all the sampling.

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Basics

QC = Quality Control = Contractor VT = Verification Test = FDOT Project

personnel (typically a consultant) IV = Independent Verification = FDOT

District Materials personnel RT = Resolution Testing = FDOT District

Materials personnel

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Typical 1,000 ton Sublot - composed of 50 truckloads (20 tons each)

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1- 1

387- 1- 1- 2

37

2310

64

85

3836

Offset (ft)

101081311

6

11

3423

1

3649

2553275428763022

- 31

1

- 3- 4- 5

3347

2332

- 3

11711368- 2

- 1- 1

473

2051

973714

- 1- 1

- 2- 2- 2

1

1

- 3

- 4- 4

11

1

11

- 3

- 3

1

1

- 2- 2

142116781881 2

- 493

1 - 4

- 2

- 2

- 3

- 3

111

- 3

- 5

Density Cores

- 5- 1

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- 4- 4

- 4

- 4

- 5- 1

1

CORE ID# (tons)

107

3Verification Sublot

Plant

1000

Sublot

1

2

3

1133

2696

37284

QC Samples

(tons)

Tons/sublot:

487

Lot 1, sublot 1

50 trucks, 20 tons each = 1,000 ton sublot

Random Sample Numbers by Sublot

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Sublot 1 Sublot 2 Sublot 3 Sublot 4

LOT = 4,000 Tons

QC randomly tests one per sublot.

VT randomly tests one split per Lot.

RT splits held until Lot is verified.

QC Testing at Plant

487 26961133 3728Tons

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Sample Splits

Gmb Gmm Ext/Grd

QC

VT

RT8

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Master Production Range for Quality Control

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Table 334-5 Master Production RangeCharacteristic Tolerance (1)

Asphalt Binder Content (%) Target ± 0.55

Passing No. 200 Sieve (%) Target ± 1.50

Air Voids (%) Coarse Graded 2.00 – 6.00

Air Voids (%) Fine Graded 2.30 – 6.00

Density, %Gmm (2)

Coarse Graded (minimum) 93.00

Fine Graded (minimum) 90.00(1) Tolerances for sample size of n = 1 from the verified mix design(2) Based on an average of 5 randomly located cores

If Quality Control Test Does Not Meet Tolerances: 334-5.4.4 (for MPR)

Terminate Lot if: One sublot failure for Air Voids. One sublot density failure. Two consecutive sublot density failures for

fine mix. Two consecutive sublot failures for

gradation. Two consecutive sublot failures for asphalt

content. 2 individual core densities for coarse mix

less than 91.00% Gmm.

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Verification Testing334-5.5

At completion of each Lot Test VT sample for randomly selected

sublot Split from QC sample

Use test method precision for comparison Excel spreadsheet

If everything compares favorably… Calculate pay based on QC results

If not….go to Resolution testing District Materials Office

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Sublot 1 Sublot 2 Sublot 3 Sublot 4

LOT = 4,000 Tons

QC tests one per sublot.

VT randomly tests one split per Lot.

VT Testing

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Between-Laboratory Precision ValuesTable 334-6

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Table 334-6Between-Laboratory Precision Values

Property Maximum DifferenceGmm 0.016

Gmb (gyratory compacted samples)

0.022

Gmb (roadway cores – fine graded mixture) 0.015

Gmb (roadway cores – coarse graded mixture) 0.018

Pb 0.44 percentP-200 FM 1-T 030 (Figure 2)P-8 FM 1-T 030 (Figure 2)

Resolution Testing334-5.6

If the verification testing does not compare on a pay property

Resolution samples tested by third party lab for the property in question All sublots are tested

Use test method precision for comparison to QC Excel spreadsheet

If everything compares favorably… Calculate pay based on QC results

If the sample does not compare Resolution results are used to calculate pay for that

property 15

Sublot 1 Sublot 2 Sublot 3 Sublot 4

LOT = 4,000 Tons

QC randomly tests one per sublot.

VT randomly tests one split per Lot.

RT tests non-comparison property for each sublot.

RT Testing

487 26961133 3728Tons

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Roadway Acceptance334-5.4.3

Roadway and Plant Lot the same.

6-inch diameter cores . Five cores per sublot.

Randomly located (stratified manner).

Use spreadsheet. Minimum of 3 cores/sublot.

Retain QC cores for VT & RT.

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Density Testing Exceptions334-5.1.2

Density testing not required for: Total quantity of hot mix < 2,000 tons. Widening or shoulders with a width of 5 ft or less. FC-5 Misc. Asphalt , Variable thickness or overbuild

layers . Leveling, Bridge Decks, Approach slabs. First lift of asphalt placed on subgrade. Bike/shared use paths. Crossovers or intersections. Any course thickness < 1 inch or specified spread

rate converts to < 1 inch. 18

Density Testing Exceptions (continued)334-5.1.2

Testing not required for the following areas when they are less than 1,000 feet long: Turning lanes Acceleration lanes Deceleration lanes Shoulders Parallel parking lanes Ramps

Use rolling procedure (equipment and pattern) as approved by the Engineer.

Density testing required everywhere else. 19

Calculate Payment334-8

If two or less sublots: Use Small Quantity Pay Table based on average

deviations from target. If three or more sublots:

Use Percent Within Limits (PWL) for the Lot. Calculate Pay Factor for:

Density, Air Voids, AC Content, P-200, P-8

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Payment….334-8

Pay factor for each characteristic is determined.

Composite Pay factor is based on: 35% Density 25% Air Voids 25% AC Content 10% P-200 5% P-8

Calculations done by spreadsheet. 21

Minimum Acceptable Quality Levels 334-5.9

Individual Pay Factors Below 0.90 First time correct, 2 consecutive – cease.

Composite Pay Factor 0.80 to 0.89 Cease until problem is resolved.

Composite Pay Factor 0.75 to 0.79 Handle per 334-5.9.5 (EAR).

Composite Pay Factor Less than 0.75 Remove and Replace.

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Defective Material 334-5.9.5

Contractor must remove & replace…OR Engineering Analysis Report…

If approved by Engineer / Paid by contractor. Independent Lab approved by Engineer. Remain in place at composite pay factor, or as

determined by Engineer. Can be waived by Engineer.

Delineation testing by Contractor Only for asphalt content, density, and

gradation.

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Independent Verification Testing334-5.7

Handled by the District Materials Office. One sample per 4,000 tons. Sampled by Contractor with FDOT

supervision. Compare IV results with QC (test precision). Use Master Production Range Table 334-5.

IF IV fails MPR, cease production until problem resolved and then evaluate in-place material.

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Friction Course 337

FC 9.5 and FC 12.5 Handled in same manner as 334 HMA.

FC 5 (OGFC) Same concepts but different material properties:▪ Asphalt content, Gradation (P-3/8, P-4, P-200)

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Questions/ Comments?

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