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Florida Department of Transportation 1 Overview of CQC Asphalt Specifications.

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Presentation on theme: "Florida Department of Transportation 1 Overview of CQC Asphalt Specifications."— Presentation transcript:

1 Florida Department of Transportation 1 Overview of CQC Asphalt Specifications

2 Florida Department of Transportation 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 In a Nutshell..

3 Florida Department of Transportation Standard Lot size: – 2,000 or 4,000 tons for dense mix or 2,000 tons for OGFC Four sublots per LOT Plant LOT & Roadway LOT are the same Engineer establishes sampling points – Random basis – Use Excel spreadsheet – Directs Contractor when to sample Contractor does all the sampling Basics

4 Florida Department of Transportation 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 Basics

5 Florida Department of Transportation Typical 1,000 ton Sublot 50 truckloads (20 tons each)

6 Florida Department of Transportation Random Sample Numbers by Sublot

7 Florida Department of Transportation QC Testing at Plant Sublot 2Sublot 3Sublot 4Sublot 1 487269611333728 Tons: LOT = 4,000 Tons QC randomly tests one per sublot VT randomly tests one split per LOT RT splits held until LOT is verified

8 Florida Department of Transportation Sample Splits G mb G mm Ext/Grd QC VT RT

9 Florida Department of Transportation

10 Roadway and Plant LOT the same 6-inch diameter cores Five cores per sublot – Randomly located (stratified manner) – Minimum of 3 cores/sublot Retain QC cores for VT & RT – Only part of the testing that is done on the same sample Roadway Acceptance 334-5.4.3

11 Florida Department of Transportation In-Place Density testing required everywhere EXCEPT Density Testing 334-5.1

12 Florida Department of Transportation Density Testing Exceptions 334-5.1.2 FC-5 Total quantity of hot mix < 2,000 tons Widening or shoulders with a width of 5 ft or less 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 NO TESTING REQUIRED IN AREAS LESS THAN 1,000 FEET LONG: Turning lanes Acceleration lanes Deceleration lanes Shoulders Parallel parking lanes Ramps

13 Florida Department of Transportation Table 334-5 Master Production Range CharacteristicTolerance (1) Asphalt Binder Content (%)Target ± 0.55 Passing No. 200 Sieve (%)Target ± 1.50 Air Voids (%)2.30 – 6.00 Density, (minimum %Gmm) (2) 90.00 (1)Tolerances for sample size of n = 1 from verified mix design (2)Based on an average of 5 randomly located cores Master Production Range

14 Florida Department of Transportation If Quality Control Test Does Not Meet Tolerances: 334-5.4.4 (for MPR) Terminate LOT if: – One sublot failure for air voids – One average sublot density failure – Two consecutive sublot failures for gradation or asphalt binder content Quality Control Test

15 Florida Department of Transportation At completion of each LOT – The LOT is “CLOSED” VT sample is tested for randomly selected sublot – Split from QC Sample Verification Testing 334-5.5

16 Florida Department of Transportation Verification Testing 334-5.5 Sublot 2Sublot 3Sublot 4Sublot 1 LOT = 4,000 Tons QC tests on per sublot VT randomly tests one split per LOT Use test method precision for comparison

17 Florida Department of Transportation Table 334-6 Between-Laboratory Precision Values PropertyMaximum Difference G mm 0.016 G mb (gyratory compacted samples)0.022 G mb (roadway cores)0.015 PbPb 0.44 percent P -200 FM 1-T 030 (Figure 2) P -8 FM 1-T 030 (Figure 2) Between-Laboratory Precision Values

18 Florida Department of Transportation If Verification compares to QC – Calculate pay based on QC results Verification Testing 334-5.5

19 Florida Department of Transportation If Verification does not compare to QC – Resolution testing – District Materials Office Verification Testing 334-5.5

20 Florida Department of Transportation Resolution Testing 334-5.6 Sublot 2Sublot 3Sublot 4Sublot 1 487269611333728 Tons: 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

21 Florida Department of Transportation Resolution samples tested by third party lab for the property in question – All sublots are tested for the failed property Use test method precision and the master production range Resolution Testing 334-5.6

22 Florida Department of Transportation Resolution compares to ALL QC data – Calculate pay based on QC results Resolution Compares to QC

23 Florida Department of Transportation Resolution does not compare to QC data – This only has to happen for one comparison – Resolution results are used to calculate pay for that property If application of Resolution test data results in a failure to meet the MPR, address as defective material. Resolution Does Not Compare

24 Florida Department of Transportation Pay Factors for Each Characteristic 334-8

25 Florida Department of Transportation Composite Pay Factor: – 35% Density – 25% Air Voids – 25% AC Content – 10% P -200 – 5%P -8 Composite Pay Factor 334-8

26 Florida Department of Transportation Individual Pay Factors Below 0.90 – First time -> correct the problem – 2 consecutive -> cease production Composite Pay Factor 0.80 to 0.89 – Cease until problem is resolved Composite Pay Factor 0.75 to 0.79 – Address defective material per 334-5.9.5 Composite Pay Factor Less than 0.75 – Remove and Replace defective LOT at no cost to the Department Minimum Acceptable Quality Levels 334-5.9

27 Florida Department of Transportation District Materials Office One sample per 4,000 tons – Roving IV = 1 / 2,000 tons Sampled by Contractor with FDOT supervision Use Master Production Range Table 334-5 – ONE IV MPR failure -> address failure and/or cease production Contractor has option to test a split sample (PC) Compare IV results with PC (test precision) IV does not affect pay calculation Independent Verification Testing 334-5.7

28 Florida Department of Transportation Independent Verification Testing 334-5.7 IV Passes MPR IV Passes MPR Continue Production IV MPR Failure IV MPR Failure No Contractor Split No Contractor Split Address Problem Contractor Split PC Compares Address Problem PC Does Not Compare Check Sample Check Compares to IV Check Does Not Compare to IV Continue Production IV Failure

29 Florida Department of Transportation 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 ) Friction Course 337

30 Florida Department of Transportation QUESTIONS/COMMENTS?


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