Overview of CQC Asphalt Specifications 1 Florida Department of Transportation

Overview of CQC Asphalt Specifications
Florida Department of Transportation
1
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
Florida Department of Transportation
Basics
• 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
Florida Department of Transportation
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
Florida Department of Transportation
Typical 1,000 ton Sublot
50 truckloads (20 tons each)
Florida Department of Transportation
Random Sample Numbers by Sublot
Density Cores
Plant
Tons/sublot: 1000
QC Samples
Sublot
(tons)
1
487
2
1133
3
2696
4
3728
Verification Sublot
3
Florida Department of Transportation
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
CORE ID#
(tons)
Offset (ft)
-1
-1
-1
-1
-1
-2
-2
-2
-2
-2
-3
-3
-3
-3
-3
-4
-4
-4
-4
-4
107
387
473
714
973
1171
1368
1421
1678
1881
2051
2332
2553
2754
2876
3022
3347
3423
3649
3836
10
10
8
1
3
11
11
9
3
2
2
3
10
6
5
8
6
4
3
7
-1
-2
-3
-4
-5
-1
-2
-3
-4
-5
-1
-2
-3
-4
-5
-1
-2
-3
-4
-5
QC Testing at Plant
LOT = 4,000 Tons
Sublot 1
Tons: 487
Sublot 2
1133
Sublot 3
2696
Sublot 4
3728
QC randomly tests one per sublot
VT randomly tests one split per LOT
RT splits held until LOT is verified
Florida Department of Transportation
Sample Splits
QC
VT
RT
Florida Department of Transportation
Gmb
Gmm
Ext/Grd
Florida Department of Transportation
Roadway Acceptance 334-5.4.3
• 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
Florida Department of Transportation
Density Cores
CORE ID#
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
-1
-1
-1
-1
-1
-2
-2
-2
-2
-2
-3
-3
-3
-3
-3
-4
-4
-4
-4
-4
-1
-2
-3
-4
-5
-1
-2
-3
-4
-5
-1
-2
-3
-4
-5
-1
-2
-3
-4
-5
(tons)
Offset (ft)
54
338
505
606
802
1037
1393
1471
1655
1932
2007
2372
2558
2754
2898
3169
3376
3476
3640
3962
2
7
3
5
9
6
11
1
9
4
6
10
4
3
6
9
8
7
9
1
Density Testing 334-5.1
In-Place Density testing required
everywhere
EXCEPT
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
Florida Department of Transportation
NO TESTING REQUIRED IN
AREAS LESS THAN 1,000
FEET LONG:
•
•
•
•
•
•
Turning lanes
Acceleration lanes
Deceleration lanes
Shoulders
Parallel parking lanes
Ramps
Master Production Range
Table 334-5 Master Production Range
Characteristic
Asphalt Binder Content (%)
Passing No. 200 Sieve (%)
Air Voids (%)
Density, (minimum %Gmm)(2)
Tolerance(1)
Target ± 0.55
Target ± 1.50
2.30 – 6.00
90.00
(1) Tolerances for sample size of n = 1 from verified mix design
(2) Based on an average of 5 randomly located cores
Florida Department of Transportation
Quality Control Test
• 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
Florida Department of Transportation
Verification Testing 334-5.5
• At completion of each LOT
– The LOT is “CLOSED”
• VT sample is tested for
randomly selected sublot
– Split from QC Sample
Plant
Tons/sublot: 1000
QC Samples
Sublot
(tons)
1
487
2
1133
3
2696
4
3728
Verification Sublot
Florida Department of Transportation
3
Verification Testing 334-5.5
LOT = 4,000 Tons
Sublot 1
Sublot 2
Sublot 3
Sublot 4
QC tests on per sublot
VT randomly tests one split per LOT
Use test method precision for comparison
Florida Department of Transportation
Between-Laboratory Precision Values
Table 334-6
Between-Laboratory Precision Values
Property
Maximum Difference
Gmm
0.016
Gmb (gyratory compacted samples)
0.022
Gmb (roadway cores)
0.015
Pb
0.44 percent
P-200
FM 1-T 030 (Figure 2)
P-8
FM 1-T 030 (Figure 2)
Florida Department of Transportation
Verification Testing 334-5.5
• If Verification compares to QC
– Calculate pay based on QC results
Florida Department of Transportation
Verification Testing 334-5.5
• If Verification does not compare to QC
– Resolution testing – District Materials Office
Florida Department of Transportation
Resolution Testing 334-5.6
LOT = 4,000 Tons
Sublot 1
Tons: 487
Sublot 2
1133
Sublot 3
2696
Sublot 4
3728
QC randomly tests one per sublot
VT randomly tests one split per LOT
RT tests non-comparison property for
each sublot
Florida Department of Transportation
Resolution Testing 334-5.6
• 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
Florida Department of Transportation
Resolution Compares to QC
• Resolution compares to ALL QC data
– Calculate pay based on QC results
Florida Department of Transportation
Resolution Does Not Compare
• 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.
Florida Department of Transportation
Composite Pay Factor 334-8
• Composite Pay Factor:
– 35%
– 25%
– 25%
– 10%
– 5%
Density
Air Voids
AC Content
P-200
P-8
Florida Department of Transportation
Minimum Acceptable Quality Levels 334-5.9
• 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
Florida Department of Transportation
Independent Verification Testing 334-5.7
• 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
Florida Department of Transportation
Independent Verification Testing 334-5.7
IV
Passes MPR
IV
MPR Failure
Continue
Production
No Contractor
Split
Address
Problem
Contractor Split
PC
Compares
PC Does Not
Compare
Check
Sample
Check Compares
to IV
Check Does Not
Compare to IV
Address
Problem
Florida Department of Transportation
IV
Failure
Continue
Production
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)
Florida Department of Transportation
QUESTIONS/COMMENTS?
Florida Department of Transportation