mte experiences with performance testing · 2018. 5. 9. · andrew hanz, mte services inc. fhwa mix...
TRANSCRIPT
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MTE Experiences with Performance Testing
Andrew Hanz, MTE Services Inc.FHWA Mix ETGFall River, MAMay 9, 2018
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Discussion Points• Overview• Summary of Performance Test Efforts
–DCT Test–SCB Test: I-FIT and Jc
• Challenges–Standardization–Implementation & Setting Limits
• Next Steps
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Performance Testing Experiences - MTE• WI & MN: High recycle projects on state highways or
county roads.–Internally developed specification that includes Hamburg,
SCB, DCT.• Iowa: Surface mixes and Interlayer
–State specifications for Hamburg and Beam Fatigue• BMD Approach
–WI & MN: Tier 3. Volumetric requirements remain, mix expected to meet or exceed the performance of a conventional mix.
– Iowa: State sets volumetric and performance test limits.
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Disc Shaped Compact Tension (DCT) TestThermal Cracking Resistance
0.0
1.0
2.0
3.0
4.0
0 0.5 1 1.5 2 2.5 3 3.5 4
Mea
sure
d L
oad
(kN
)
CMOD(fit) (mm)
Binder 2Binder 1
Fracture Energy = Area Under Curve to
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Test Implementation - DCTProcedure and Specification
Test Procedure
• Temperature: LT PG + 10°C • Aging: AASHTO R30 Short Term
– Long term aging done for research.
• Air voids: Design + 3%• Detailed procedures in place for
conditioning time and duration samples can be held at low temps.
Specification
• Previous iterations included a min. fracture energy of 690 J/m2
• MTE draft specification compares to a conventional mix.
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Test Implementation – DCTEvaluation #1 – Effect of Mix Design Factors
Statistic Peak Load (kN)Time at Peak Load (secs)
Fracture Energy (J/m2)
Average 3.27 7.58 542Range 0.23 0.38 43Std Dev 0.08 0.15 15.67COV 2.5% 2.0% 2.9%
PBRPG 58-34 (LT
Continuous Grade -34.9)
15 -32.730 -30.650 -27.7
Max Deviation from Plan Grade (°C) 6.3
Factors Studied• Binder Replacement (RAP): 15%, 30%, 50%• Aging: Short Term (4 hrs @ 135C), Long Term
(12 hrs @ 135C)• Polymer Modification: PG 58S-34, PG 58V-34
Recovered Binder Data
Results
Bahia et. al, WHRP 15-04 Study (3)
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Test Implementation – DCTEvaluation #1 – Effect of Mix Design Factors
FactorGeneral Trend
Peak Load Time to Peak Load Fracture Energy
Increase PBRPG 58-28: No trend.PG 58-34: No trend.
PG 58-28: Decrease (0.70s)PG 58-34: Decrease (0.33s)
PG 58-28: Increase (31 J/m2)PG 58-34: Decrease (42 J/m2)
Increase Aging
PG 58-28: Increase (0.06 kN)PG 58-34: Decrease (0.05 kN)
PG 58-28: Decrease (0.15s)PG 58-34: Decrease (0.37s)
PG 58-28: Decrease (48 J/m2)PG 58-34: Decrease (14 J/m2)
Use of Modification
PG 58-28: Increase (0.26 kN)PG 58-34: Increase (0.08 kN)
PG 58-28: Decrease (0.60s)PG 58-34: Decrease (0.11s)
PG 58-28: Decrease (24 J/m2)PG 58-34: Decrease (28 J/m2)
Highlight = Inconsistent Trend Between Binder Grades Bahia et. al, WHRP 15-04 Study (3)
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Test Implementation – DCTEvaluation #2 – Aging and Aggregate Type
Granite• LAR @ 500 = 18.3• Fracture Energy (12 hr)
= 551 J/m2
Limestone• LAR @ 500 = 32.0• Fracture Energy (12 hr) =
360 J/m2
• Factor driving fracture energy depends on aggregate type.
• Hard aggregate = Mastic Failure.• Soft Aggregate = Coarse aggregate
fracture.
Refer to TRB Paper by Braham (2001)
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Test Implementation – DCTEvaluation #2 – Aging and Aggregate Type
• Limestone Aggregate: LAR @ 500 = 32%
• Gravel Aggregate: LAR @ 500 = 15%
• All aging was loose mix at 135°C
0
100
200
300
400
500
600
700
800
Limestone 12.5mmE1
Limestone 19.0 mmE0.3
Gravel 12.5 mm E3
Frac
ture
Ene
rgy
(J/m
2)
Reheat 12 hour Aging 24 Hour Aging
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Test Implementation – DCTEvaluation #3 – MnDOT Report
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Test Implementation – DCTObservations and Discussion
• Recent discussion has suggested reducing fracture energy requirements from initial targets:
– Benefits: Accommodates “soft” aggregates such as limestone.– Risks: If hard aggregate is used there is potential that an inferior mix
(i.e. high binder replacement or low binder content) would still pass specification limit.
• Implications of changing/eliminating aggregate sources.• Recommended Action: Universal limit is not feasible. Compare to mixes
of known performance.
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SCBIntermediate Temperature Cracking Test• Test Methods Evaluated
– ASTM D8044: LSU Procedure, 3 notch depths, 0.5 mm/min loading rate.– AASTHO TP 124: I-FIT, one notch depth, 50 mm/min loading rate.
• Factors Evaluated: Binder Replacement, Polymer Modification, Aging
0.00.20.40.60.81.01.2
20.0 25.0 30.0 35.0 40.0
Stra
in E
nerg
y (k
J)
Notch Depth (mm)
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SCB - LSUAdjusting for a Northern Climate• Test temperature was adjusted to PG Inter. Temp to account for use of
softer grades in WI. • Three independent studies:
– WisDOT High RAM Pilot Program (AAPT 2015)– WHRP Performance Testing Feasibility Project (2016)– WHRP Durability Project – Bonaquist (2016 & 2016 AAPT Paper)
• Studies found the test was insensitive to the variables studied.• Example of the localized development of these tests and potential
complications in implementation.
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SCB – D8044ILS 1424 – Phase 1
• Three samples:
• 12 laboratories
Steel Sample Plastic Sample Plastic Sample w/notchLoading Rate 0.5mm/min Loading Rate 0.5mm/min Loading Rate 0.5mm/min
Sampling Rate 10/sec Sampling Rate 10/sec Sampling Rate 10/secLoad limit 500N, 1000N, 2500N Load limit 1500N Load limit 1000N
Gage Length 127mm (5") Gage Length 127mm (5") Gage Length 127mm (5")Temperature Room Temperature Temperature Room Temperature Temperature Room Temperature
Pre-load 45± 10N Pre-load 45± 10N Pre-load 45± 10N
Procedure
Steel SamplePlastic SamplePlastic Sample w/notch
Loading Rate0.5mm/minLoading Rate0.5mm/minLoading Rate0.5mm/min
Sampling Rate10/secSampling Rate10/secSampling Rate10/sec
Load limit500N, 1000N, 2500NLoad limit1500NLoad limit1000N
Gage Length127mm (5")Gage Length127mm (5")Gage Length127mm (5")
TemperatureRoom TemperatureTemperatureRoom TemperatureTemperatureRoom Temperature
Pre-load45± 10NPre-load45± 10NPre-load45± 10N
ProcedureZero load, and load sample into fixture (with or without teflon)
Apply pre-load. Once achieved zero load again and zero displacement.
Start test and run until set load limit is reached.
Repeat at least 3 tests at each load limit
ReportGraph Load vs Displacement and add a linear trendline to each test to get slope.
Graph Displacement vs time to show displacement rate. Average entire displacement rate column to get average displacement rate.
Report slope for each test and average slope between all tests.
Template
Name:e-mail:
Lab Name:Tel. No.:
Date:
Testing Frame (manufacturer, model):
Temperature Chamber (if available: manufacturer, model):
Testing Temperature:Room or Temperature Chamber Controlled?
ASTM ILS 1424
Time ExtensionLoadDisplacement RateTime ExtensionLoadDisplacement RateTime ExtensionLoadDisplacement Rate
ERROR:#DIV/0!
ERROR:#DIV/0!
ERROR:#DIV/0!ERROR:#DIV/0!ERROR:#DIV/0!
ERROR:#DIV/0!ERROR:#DIV/0!
ERROR:#DIV/0!ERROR:#DIV/0!
Load vs Displacement
Run 1Run 2Run 3
Displacement (mm)
Load (N)
Displacement Rate
Run 1Run 2Run 3
Time (secs)
Displacement (mm)
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SCB – D8044ILS 1424 – Phase 1
Results to date from 6 laboratories• Testing Devices
1- AMPT1- MTS2 – Brovold1 – Instron1- IPC-Global1 - Instrotek
• Testing Fixtures7 – fixed rollers3 – rollers with springs1 – 36mm roller
Material x¯ r-COV% R-COVValidator 300 24.3 57.0
Plastic with notch 58 26.6 102.1Plastic with notch 111 45.5 122.7
average 32.1 93.9
Sheet1
E691 Precision and Bias Analysis - SCB Strain Energy
Calibrator
Sample 1Sample 2Sample 3Sample 4Sample 5Average sdhk
LMLab 1308.2300.9300.9303.34.23.00.050.16
LALab 2325.8320.2328.5324.84.224.40.430.16
BLab 3323.6318.3323.7321.93.121.50.370.12
MILab 4311.8306.6307.8308.82.78.40.150.10
MI-sprLab 5445.9374.4366.6395.643.795.21.661.67
MI-spr3Lab 6338.3336.7336.2337.11.136.70.640.04
PGLab 7194.7211.8200.2202.28.8-98.1-1.710.34
IBLab 8234.6234.0231.5233.41.7-67.0-1.170.06
AILab 9278.5275.6275.1276.41.8-24.0-0.420.07
Average of Cell Averages, x¯300
Standard Deviation of Cell Averages, sx¯57COV%95% Conf
Repeatability Standard Deviation, sr268.724.3
Reproducibility Standard Deviation, sR6120.357.0
95% Repeatability Limit, r73
95% Reproducibility Limit, R171
Plastic- Notch
Sample 6Sample 7Sample 8Sample 9Sample 10Average sdhk
LMLab 157.658.353.756.52.5-1.0-0.00.5
LALab 265.860.963.063.22.55.70.30.5
BLab 340.139.239.439.50.5-18.0-0.90.1
MILab 466.264.463.564.71.47.20.40.3
MI-sprLab 562.759.158.260.02.42.50.10.4
MI-spr3Lab 669.466.665.567.22.09.60.50.4
PGLab 7100.688.1103.197.38.139.71.91.5
IBLab 823.724.224.024.00.3-33.5-1.60.0
AILab 945.544.945.445.30.3-12.2-0.60.1
Average of Cell Averages, x¯57.5
Standard Deviation of Cell Averages, sx¯20.5COV%95% Conf
Repeatability Standard Deviation, sr5.59.526.6
Reproducibility Standard Deviation, sR21.036.5102.1
95% Repeatability Limit, r15.3
95% Reproducibility Limit, R58.7
Plastic
Sample 11Sample 12Sample 13Sample 14Sample 15Average sdhk
LMLab 196.4150693.0825492.9418694.12.0-17.3-0.40.1
LALab 2132.338121.1045111.2045121.510.610.10.20.6
BLab 370.02864.016563.674565.93.6-45.5-1.00.2
MILab 4144.7496139.3661138.8242141.03.329.60.60.2
MI-sprLab 5141.6595134.0093136.3845137.43.925.90.60.2
MI-spr3Lab 6130.6145125.6587125.1613127.13.015.70.30.2
PGLab 7222.9531166.9393185.2165191.728.680.31.71.6
IBLab 833.93932.385531.325532.61.3-78.9-1.70.1
AILab 992.9132590.8160190.5595191.41.3-20.0-0.40.1
Average of Cell Averages, x¯111.4
Standard Deviation of Cell Averages, sx¯46.5COV%95% Conf
Repeatability Standard Deviation, sr18.116.245.5
Reproducibility Standard Deviation, sR48.843.8122.7
95% Repeatability Limit, r50.7
95% Reproducibility Limit, R136.7
h-value Tablek-value Table
Material AMaterial BMaterial CMaterial AMaterial BMaterial C
Lab 10.05-0.05-0.37Lab 10.160.450.11
Lab 20.430.280.22Lab 20.160.450.58
Lab 30.37-0.88-0.98Lab 30.120.090.20
Lab 40.150.350.64Lab 40.100.250.18
Lab 51.660.120.56Lab 51.670.440.22
Lab 60.640.470.34Lab 60.040.370.17
Lab 7-1.711.941.72Lab 70.341.481.58
Lab 8-1.17-1.64-1.69Lab 80.060.050.07
Lab 9-0.42-0.60-0.43Lab 90.070.060.07
Precision Statistics
2ds2ds2ds2ds
Materialx¯sx¯srsRrRr (Within)R (Between)r-COV%r-COV
A30057266173171206.8484.124.357.0
B5820521155943.2166.126.6102.1
C11147184951137143.4386.845.5122.7
Average131.1345.632.193.9
2ds2ds
Materialx¯r-COV%R-COV
Validator30024.357.0
Plastic with notch5826.6102.1
Plastic with notch11145.5122.7
average32.193.9
h-Table
Lab 1
Material AMaterial BMaterial C5.1552044853934574E-2-4.8448383874926754E-2-0.37106824316525122Lab 2
Material AMaterial BMaterial C0.426149695404568760.278249272821019580.21766506677663616Lab 3
Material AMaterial BMaterial C0.37486920986762523-0.87708043083420351-0.97779795233303879Lab 4
Material AMaterial BMaterial C0.146250791788091220.350206684163343880.63513251517749381Lab 5
Material AMaterial BMaterial C1.66243628809120560.120571159101740650.55716759794467885Lab 6
Material AMaterial BMaterial C0.640595044788427210.47054913084704780.33788956735954417Lab 7
Material AMaterial BMaterial C-1.71342504133332191.93908656010768991.7248982354574955Lab 8
Material AMaterial BMaterial C-1.169972583361035-1.6356339485416866-1.6944469798136654Lab 9
Material AMaterial BMaterial C-0.41845545009948981-0.5975000437900253-0.4294398074038871
k-Table
Lab 1Material AMaterial BMaterial C0.162117545330949940.450358818630673340.10860773900107845Lab 2Material AMaterial BMaterial C0.162401464209355970.454086834400570180.58415564191477265Lab 3Material AMaterial BMaterial C0.11792718696768168.7822342053975821E-20.19742421888573772Lab 4Material AMaterial BMaterial C0.104489111035639720.250120251171783270.18097540493214206Lab 5Material AMaterial BMaterial C1.6731138005923440.438147248168169250.21632182855251569Lab 6Material AMaterial BMaterial C4.1986667050792591E-20.37167559420356350.16657123319614361Lab 7Material AMaterial BMaterial C0.335479444028734311.47814434518806341.5780793109372613Lab 8Material AMaterial BMaterial C6.4229476606337252E-24.7066672069199025E-27.2620174096601778E-2Lab 9Material AMaterial BMaterial C6.9096434016894387E-25.8884991810675177E-27.1337333314237458E-2
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SCB – D8044ILS 1424 – Phase 1
Results to date from 6 laboratories• Testing Devices
1- AMPT1- MTS2 – Brovold1 – Instron1- IPC-Global1 - Instrotek
• Testing Fixtures7 – fixed rollers3 – rollers with springs1 – 36mm roller
0.00
0.20
0.40
0.60
0.80
1.00
1.20
1.40
1.60
1.80
Material A Material B Material C
k-Table
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SCB-IFITInitial Evaluations • Benefits
– Identifies mixes that are too stiff. – Verifies design vs. production– Provides a relatively easy way to evaluate mix composition.
• Concerns– Repeatability– Polymer modification (Discussed in Fall 2017 meeting)– Aging– Refining limits.
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SCB - IFITRAP/RAS Content & Volumetrics
Mix Design
AB (%)
%AV at Ndes VMA VFA
RCY AB (%) ABR
RAP RAS Total RAP RAS Total
N50 5.8 3.6 15.1 73.5 1.2 0.8 2.00 20.3 14.0 34.3
N70 5.9 3.5 15.3 73.9 0.6 0.0 0.6 9.6 0 9.6
• Aggregate structure • Recycled products and ABR values for mix designs:
‒ N50 has 34% PBR, 40% of the binder replacement is from RAS.
Differences
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SCB I-FITEffect of PBR - Flexibility Index
241 81 260
0.1 6
0.1 4
0.1 2
0.1 0
0.08
0.06
0.04
0.02
0.00
5.730 2.564 321 3.56 4.895 32
Mean StDev N
F
ytisneD
xednI ytilibixel
NepyT xiM
07N05
H lamroN
xednI ytilibixelF fo margotsi
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SCB I-FitPotential Benefits to Monitor Production
Factors Levels
Mix Design Variables
Aggregate Source: Granite, Gravel, Limestone
Mix Traffic Level Medium Traffic and High Traffic
Production Variables
Asphalt Binder Content Design – 0.3%, Design, Design + 0.3%
P200 Content Design -2%, Design, Design + 2%
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SCB I-FitPotential Benefits to Monitor Production
Factors Flexibility Index Post-Peak Slope Fracture Energy
Mix Type/Modification P-value Sig? P-Value Sig? P-value Sig?
Aggregate Source
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SCB I-FIT ConcernsRepeatability – Single Lab
Base BinderPolymer
PG 64-22PG 58-28SBSNone51 7051 60SBSNone51 7051 60
1 2
1 0
8
6
4
2
Flex
ibili
ty In
dex
Boxplot of Flexibility Index
Base BinderPolymer
PG 64-22PG 58-28SBSNone51 7051 60SBSNone51 7051 60
30
25
20
1 5
1 0
Flex
ibili
ty In
dex
Boxplot of Flexibility Index
N50 N70
Four replicates tested for all mixes.
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SCB I-FIT ConcernsAging
• Is Flexibility Index a discriminating property on long term aged samples?• Data represents ~12 designs. 4% AV and 3.0% Regressed AV contents.
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SCB IFIT ConcernsEffects of Loading Rate and Aging
• After aging Flexibility Index values collapse due to stiffness effect.
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ChallengesStandardization• HMA acceptance based on volumetrics causes plenty of disputes due
to multi-lab variability and differing practices.• Adoption of even simple performance tests introduces more
complexity.• Have been successful in generating test procedures.
– Need to understand precision and bias, ruggedness, etc.
• Assign testing responsibility and at what point in the process it will occur.
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ChallengesImplementation Approach and Value Added
1. Maintaining current specifications and adding performance test requirements.a. Pro: Good for initial data gathering.b. Cons: Limited flexibility for mix adjustments.
Performance Test Limits
Volumetric Requirements
Long Term OutcomesChange in specifications based on initial performance test results.
OrBMD Approach #2: Relax volumetric criteria and add performance test requirements.
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ChallengesOne Size Does Not Fit All – Setting Limits
• Dense Graded Mixes– Surface Layers vs. Lower Layers– Mix Traffic Level– Should effects of load/moisture be combined?
• Specialty Mixes– Interlayer, Thinlay, SMA
• Example– Flexibility Index = 7.0 (Dense Graded Mix) or 20.0 (SMA).
• Different Tests may be better suited for different applications.
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Next StepsIdeal Process
Rutting (Stiffness)Cracking (Compliance)
Moisture DamageWhich test?
Aging Protocol?Aging Evaluation – Mixture or
Binder?
1. Selection of Binder Grade and Binder Content
2. Quality Assessment
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Next StepsQuality Assessment - Gaps
• Moisture Damage– Combined with Rutting by using wet Hamburg with very high # of
passes.– Is specification promoting dry/stiff mixes?– Should effects of load/moisture be combined?
• Aging/Durability– Significant debate on which aging method to use and aging binder or
mix.– Many index cracking tests have not been developed at the levels of
aging currently under consideration.– Interim solution? Binder properties (i.e. ΔTc, G-R) have shown good
correlation to field performance.
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Remarks/Discussion Points• There are benefits to single loading rate/single temperature
tests, but they cannot solve all problems. – Evaluates the mix as a system & Provides a control for mix
stiffness.• A solution for aging resistance is still a major research need.
– Accelerated load correlations indicate load associated cracking.• States are looking for guidance on how to incorporate these
tests into practice.
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Thank You!Andrew Hanz, Ph.D.Technical DirectorMTE Services Inc.
mailto:[email protected]
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References
1. Braham, A., Buttlar, W. G. & Marasteanu, M., 2007. Effect of Binder Type, Aggregate, and Mixture Composition on Fracture Energy of Hot-Mix Asphalt in Cold Climates. Transportation Reserach Record, Journal of the Transportation Research Board, Volume 2001, pp. 102-109.
2. Johanneck, L. et al., 2015. DCT Low Temperature Fracture Testing Pilot Project, St. Paul Minnesota: Minnesota Department of Transportation.
3. Bahia, et. al, “Analysis and Feasibility of Asphalt Pavement Performance Based Specifications for WisDOT”. Wisconsin Highway Research Program Proj. 0092-15-04. December 2016.
4. Mandal, T., Hanz, A. Bahia, H., “Challenges in using the DCT test to Determine the Role of Asphalt Mix Design Variables in Cracking Resistance at Low Temperatures.” International Journal of Engineering, Taylor & Francis 2017. ISSN: 1029-8436.
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References
5. Hanz, A., Dukatz, E., Reinke, G., “Use of Performance-Based Testing for High RAP Mix Design and Production. Journal of Road Materials and Pavement Design, Volume 18: Papers from 91st AAPT Meeting, 2017.
6. Bonaquist, R., Paye, B., Johnson, C. “Application of InterdmediateTemperature SCB Test Results to Design Mixtures with Improved Load Associated Cracking Resistance.: AAPT Meeting 2017.
7. Bonaquist, Critical Factors Affect.ing Asphalt Concrete Durability. Wisconsin Highway Research Program Report 0092-14-06, WisDOT, 2016
8. Mandal, T., Hanz, A. Bahia, H., “Challenges in using the DCT test to Determine the Role of Asphalt Mix Design Variables in Cracking Resistance at Low Temperatures.” International Journal of Engineering, Taylor & Francis 2017. ISSN: 1029-8436.
MTE Experiences with Performance TestingDiscussion PointsPerformance Testing Experiences - MTEDisc Shaped Compact Tension (DCT) Test�Thermal Cracking ResistanceTest Implementation - DCT�Procedure and SpecificationTest Implementation – DCT�Evaluation #1 – Effect of Mix Design FactorsTest Implementation – DCT�Evaluation #1 – Effect of Mix Design FactorsTest Implementation – DCT�Evaluation #2 – Aging and Aggregate TypeTest Implementation – DCT�Evaluation #2 – Aging and Aggregate TypeTest Implementation – DCT�Evaluation #3 – MnDOT ReportTest Implementation – DCT�Observations and DiscussionSCB�Intermediate Temperature Cracking Test SCB - LSU�Adjusting for a Northern ClimateSCB – D8044�ILS 1424 – Phase 1SCB – D8044�ILS 1424 – Phase 1SCB – D8044�ILS 1424 – Phase 1SCB-IFIT�Initial Evaluations SCB - IFIT�RAP/RAS Content & VolumetricsSCB I-FIT�Effect of PBR - Flexibility IndexSCB I-Fit�Potential Benefits to Monitor ProductionSCB I-Fit�Potential Benefits to Monitor ProductionSCB I-FIT Concerns�Repeatability – Single LabSCB I-FIT Concerns�AgingSCB IFIT Concerns�Effects of Loading Rate and AgingChallenges�StandardizationChallenges�Implementation Approach and Value AddedChallenges�One Size Does Not Fit All – Setting LimitsNext Steps�Ideal ProcessNext Steps�Quality Assessment - GapsRemarks/Discussion PointsThank You!ReferencesReferences