moisture damage in asphalt pavements: forensic analyses...
TRANSCRIPT
Moisture Damage in Asphalt Pavements: Forensic Analyses and Research Needs
Wednesday, October 31, 20182:00-4:00 PM ET
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and attended the entire session. As such, it does not include content that
may be deemed or construed to be an approval or endorsement by RCEP.
Purpose
Provide a practical discussion of moisture damage in asphalt pavements.
Learning ObjectivesAt the end of this webinar, you will be able to:
• Identify moisture-related damage in asphalt pavements• Describe various methods to make asphalt pavements less
susceptible to moisture damage and understand the steps to address moisture damage taken by state highway agencies
• Discuss a cost-benefit analysis performed to determine the applicability of anti-strip additives
• Discuss the existing research related to asphalt moisture damage and identify gaps
Moisture Damage in Asphalt Pavements
Concepts and fundamentals
Silvia CaroTRB Webinar — October 2018
Definition
Definition
Moisture damage is a degradation process that leads to the overall degradation of the mechanical properties of the material due to the
presence of moisture in a any state (liquid, vapor, solid).
“the progressive functional deterioration of a pavement mixture by loss of the adhesive bond between the asphalt cement and the aggregate surface
and/or loss of the cohesive resistance within the asphalt cement, principally from the action of water.”
— Kiggundu and Roberts (1988)
Factors impacting moisture damage susceptibility
Materials components of the mixture
Properties of individual phases, Volumetric properties, Type of mixture, etc.
Moisture Damage
System attributes intrinsic factors
Factors impacting moisture damage susceptibility
Moisture Damage
Construction procedures and quality control
Methodologies, Compliance QA
regulations.
Extrinsic factors impacting internal factors
Factors impacting moisture damage susceptibility
Project characteristics
Project relevance/traffic, Supporting systems (drainage), Maintenance strategies.
Moisture Damage
Extrinsic factors
Factors impacting moisture damage susceptibility
Environment
Relative humidity Rainfall regimes Water table Winter regimens (freeze-
thaw cycles, etc.)
Moisture Damage
https://imagens-de-fundo.blogspot.com/2011/07/imagem-de-fundo-nuvens-brancas-em-ceu.html
Extrinsic factors
Moisture damage mechanisms
https://pixabay.com/en/clock-mechanism-gears-976234/
Mechanisms
Moisture Damage Mechanisms
Water transport modes
System attributes
Response of the system Water infiltration
Vapor water diffusion Capillary rise
Aggregate mineralogy Asphalt properties Mixture volumetric
properties
DistressesExtrinsic Factors
Construction Weather Traffic
Debonding
Cohesive degradation
aggregate
Asphalt coating
Moisture
https://www.pavementinteractive.org/reference-desk/testing/asphalt-tests/moisture-susceptibility/
Distresses – damage manifestation
Stripping, raveling.….. potholes
https://indianapublicmedia.org/news/indianapolis-extra-145m-deal-potholes-143888/
Summary
Moisture Damage Mechanisms
Water transport modes System attributes
Moisture damage is a complex phenomenon that involves physical, chemical,
thermodynamics and mechanical processes, each one occurring at a different magnitude and rate.
Main difficulty for finding ‘the’ best moisture susceptibility test
Project or extrinsic factors (weather, traffic)
&
FORENSIC INVESTIGATION OF HMA RAVELING AND MOISTURE DAMAGE IN MAINEDerek Nener-Plante, M.S., P.E.Asphalt Pavement EngineerMaineDOT
1
Integrity – Competence - Service
Talking Points2
MaineDOT Background Maine Raveling Issue Forensic Study - Methodology Observations / Conclusions Questions
Background - MaineDOT3
Responsible for over 8,400 centerline miles of the 24,000 total miles in Maine
Average capital program of $269 million per year
Superpave mix design – full QA system on volumetrics
What is the problem?
Raveling of the HMA surface, primarily from the wheelpaths
Two different loss components: Coarse aggregate Matrix
Statewide PMS data shows a marked increase in rutting
No current moisture damage test used in Maine
4
HMA Raveling5
HMA Raveling6
HMA Raveling7
HMA Raveling - Interstate8
HMA Raveling - Interstate9
HMA Raveling - Differing Texture10
HMA Raveling Impact
Numerous major failures in Region 5
High profile failure in Bangor on I-95 Mill & Fill paved in
2007-2008 Required partial
repair in 2012 UTBWC in 2014
Statewide in at least some severity
11
HMA Raveling - Forensic Study12
Partnership with FHWA – formed a team Tim Aschenbrener, FHWA Office of Pavement
Technology Mike Praul, FHWA Division Office Rick Bradbury, Materials Engineer Brian Luce, Pavement Quality Derek Nener-Plante, Asphalt Pavement Engineer Kevin Cummings, Quality Assurance John Bither, Region 5 Project Manager Bruce Yeaton, Consultant
Project List13
ID Route: Nearby City Age Treatment Raveling Rut
G1 1A: Dedham-Ellsworth 8 6” HMA and ABC Very Low 3/16”
G2 1: Mars Hill 10 6” HMA and ABC Very Low
G3 9: Augusta 8 1-1/2” mill and shim*
Low 4/16”
M1 1A: Ellsworth 4 6” HMA and ABC Low - Mod 4/16”
M2 163: Castle Hill 5 6” HMA and ABC Low - Mod 4/16”
M3 9: Chelsea 3 ¾” and shim Low - Mod 2/16”
P1 1: Westfield 5 ¾” and shim Gone 16/16”
P2 163: Mapleton - Presque Isle
10 1-1/4” mill and shim Gone 20/16”
Poor Performers14
P1P2
Possible Causes15
Climate and Traffic High moisture
environment Studded tires
Construction Factors Time of paving along
with mixing, compaction and ambient temperatures In-place density
Constructability including joints, segregation and mat tearing
Increase in percent passing No. 200 sieve
Aggregate Properties Quality of P200 Dust coating Durability Thickness of overlay to
nominal maximum aggregate size (t / NMAS) along with fine and coarse gradations
Possible Causes (continued)16
Binder Properties Performance grading Reclaimed binder ratio (RBR) Chemistry of binder: re-refined
engine oil bottoms (REOB) Chemistry of binder:
polyphosphoric acid (PPA) Chemistry of binder: presence
of copper Rapid-aging of the binder from
drum mixer or silo storage Difference in critical low
temperature (∆Tc)
Mixture Volumetric Properties Asphalt content Air voids Voids in the mineral aggregate
(VMA) Aggregate bulk specific
gravity (Gsb) Dust to asphalt ratio (F / Be)
Mixture Characterization Permeability Moisture susceptibility
measured with the tensile strength ratio
Moisture susceptibility measured with Hamburg wheel-track testing
Causes Related to Performance17
1) Quantity of P200 with F/Be2) Aggregate durability with
the Micro-Deval abrasion loss
3) thickness / NMAS4) Gsb verification5) Permeability6) Moisture susceptibility
testing
1) Quantity of P200 with F/Be18
50
60
70
80
90
100
G1 G2 G3 M1 M2 M3 P1 P2
PWL
for
F/Be
Project ID
* Taken from Acceptance testing results LSL = 0.6, USL = 1.2
1) Quantity of P200 with F/Be19
* Increase = P200 (Acceptance) – P200 (Design)
0.0
0.5
1.0
1.5
2.0
2.5
G1 G2 G3 M1 M2 M3 P1 P2
Incr
ease
in P
200
(%)
Project ID
2) Aggregate Durability20
* Blend – composite design at approval / Source – individual source aggregate
05
1015202530
G1 G2 G3 M1 M2 M3 P1 P2
Loss
(%
)
Project ID
Blend (Project) Coarse (Source)
2) Aggregate Durability21
* Performed on residual agg. after solvent extraction of forensic cores
0.0
5.0
10.0
15.0
20.0
G1 G2 G3 M1 M2 M3 P1 P2
Loss
(%
)
Project ID
Fine Micro-Deval (ASTM D7428)
3) Thickness / NMAS22
* P2 – NMAS changed during construction from 9.5 mm to 12.5 mm
0.00.51.01.52.02.53.03.54.0
G1 G2 G3 M1 M2 M3 P1 P2
t / N
MA
S
Project ID
4) Gsb Verification & Volumetrics23
MaineDOT Policy:
Contractor submitted Gsb is used for calculation – must
be within 0.02 of MaineDOT value to verify
8 of 9 projects had Contractor values higher
than the DOT values2.55
2.60
2.65
2.70
2.75
2.80
2.85
2.55 2.65 2.75 2.85
Con
trac
tor G
sb
MaineDOT Gsb
5) Permeability24
* Calculated based upon NMAS & in-place density (NCAT, Mallick, 2003)
0
50
100
150
200
250
G1 G2 G3 M1 M2 M3 P1 P2
Perm
eabi
lity
(x10
E-05
)
Project ID
6) Moisture Susceptibility Testing25
* AASHTO T 283 TSR from remolded, forensic cores
0.00
0.20
0.40
0.60
0.80
1.00
1.20
G1 G2 G3 M1 M2 M3 P1 P2
Tens
ile S
tren
gth
Ratio
Project ID
6) Moisture Susceptibility Testing26
* G3 & M1 had no SIP identified
0
5
10
15
20
G1 G2 G3 M1 M2 M3 P1 P2
Strip
ping
Infle
ctio
n Po
int
Thou
sand
s
Project ID
Preservation Projects
6) Moisture Susceptibility Testing27
Plastic Flow28
Stripping29
Stripping30
Findings - Reconstruction Projects31
G1 G2 M1 M2Construction F/Be PWL 100 100 72 72Aggregates Durability C C F
t / NMAS 3 3 3 3Volumetric Properties
Gsb
Mixture Properties
PermeabilityHamburg * *
Findings - Preservation Projects32
G3 M3 P1 P2Construction F/Be PWL 100 75 63 65Aggregates Durability C C F C F
t / NMAS 3 2 3 2.4VolumetricProperties
Gsb
Mixture Properties
PermeabilityHamburg
Recommendations33
Improve the weighting of pay factors for control of the P200, either the ∆P200 or F / Be.
Improve the verification process for the Gsb. Implement moisture susceptibility testing such as the
Hamburg wheel-track testing using the stripping inflection point.
Implement aggregate durability test for fine and coarse aggregates such as the Micro-Deval.
Establish guidelines for the use of thin overlays that includes the t / NMAS and gradation (coarse vs. fine).
Not one thing will “fix” all of Maine’s HMA issues
Mixtures selected on basis of historic performance in terms of moisture susceptibility
Various moisture susceptibility tests evaluated
Research Team: Eshan V. Dave (PI), Chris DeCarlo, Jo Sias Daniel (CoPI) from University of New Hampshire -Rajib Mallick (CoPI), Ram Kumar Veeraragavan, Nivedya MadankaraKottayi from Worcester Polytechnic Institute
NETC 15-3: Moisture Susceptibility Testing for Hot Mix Asphalt Pavements in New England
AASHTO T283 No clear distinction between good and poor mixes.
Hamburg Wheel Tracker Clear distinction between good and poor performers
MiST conditioning has good potential to discriminate between mixtures, especially when combined with Ultrasonic Pulse Velocity (UPV) test
NETC 15-3:Outcomes
Any Questions?
Derek Nener-Plante, M.S., PEAsphalt Pavement Engineer
Thank you for the opportunity.36
Evaluating Performance of Asphalt Pavements in Arkansas
TRB Webinar: Moisture Damage in Asphalt Pavements: Forensic Analyses and Research Needs
October 31, 2018
Andrew Braham, University of ArkansasZahid Hossain, Arkansas State University
Timothy Aschenbrener, Federal Highway Administration
vs.(I-30 east of Little Rock)
(I-40 west of Little Rock)
Acknowledgements
• Shu Yang and Nazmul Chowdhury – graduate students on project
• Leslie Parker, Slater Smith, Cory Bramlett, Erica Yeung, Marius Kabera, Chris Siebenmorgen and Seth Cagle –undergraduate students
• ArDOT (Arkansas Department of Transportation)- Funded TRC research project 1404- Mark Greenwood (research project coordinator)- Crews that helped with sampling (250+ cores)
2
From 2000 – 2005, Arkansas completed an Interstate Rehabilitation Program (IRP)
(Wilson, 2002)
3
Some roads are doing just fine from the IRP
4
I-30 near Brinkley, AR
Unfortunately, other roads are prematurely deteriorating – why?
5
I-40 near Ozark, AR
Interstate locations sampled
6
Four good sections, two medium sections, four poor sections
(map from: googlemaps.com)
Analysis focused on the following
• Structural adequacy• In-place air voids• Moisture damage• Lack of bond strength• Mix properties
- Lab mix design- Field acceptance
7
Did these factors influenced deterioration?
Analysis focused on the following
• Structural adequacy• In-place air voids• Moisture damage• Lack of bond strength• Mix properties
- Lab mix design- Field acceptance
8
Structural adequacy:Typical thicknesses
• Surface course (S2): 1-2”• Surface course (S1): 1.5-3”• Binder course (B3): 3”• Binder course (B2): 4”• Base course (B1): NA to 3”
9
Structure adequate:Not a structural issue
Analysis focused on the following
• Structural adequacy• In-place air voids• Moisture damage• Lack of bond strength• Mix properties
- Lab mix design- Field acceptance
10
In-place air voids
• After approximately fifteen years of traffic• After this time period, air void evaluation:
- Good performance < 7%- Medium performance 7-8%- Poor performance ≥ 8%
• Two analysis slides:- Color representation- Graphical representation
11
Air voidsGreen good, , red poor
12
• Poor performing sections had poor levels of air voids
• Good performing sections had good levels of air voids
Analysis focused on the following
• Structural adequacy• In-place air voids• Moisture damage• Lack of bond strength• Mix properties
- Lab mix design- Field acceptance
13
Moisture damage
• Visual rating:- Stripping rating from
fracture samples- Stripping rating from
AASHTO T283- Performance
o Good 1-2o Medium 3o Poor 4-5
14
• Core degradation:- By photo observation of
cores- Performance
o Good: intact core with smooth sides
o Moderate: separation of lifts and smooth sides
o Severe: separation and degradation form an hour-glass shape
o Very severe: hour-glass shape and/or substantial loose material
Moisture damageGreen good, , red poor
15
• Poor performing sections had poor levels of stripping ratio
• Good performing sections had good levels of stripping rating
Moisture damage: core degradation
16
G1Good: intact core with smooth sides
M1Severe: separation
and degradation form an hour-glass shape
P4Very severe:
hour-glass shape and/or substantial
loose material
Analysis focused on the following
• Structural adequacy• In-place air voids• Moisture damage• Lack of bond strength• Mix properties
- Lab mix design- Field acceptance
17
Layer debonding
• Debonded lifts:- Cores arrive in lab
debonded- “Zero” bond strength- Performance
o Good ≤20%o Medium 20 – 35%o Poor ≥35%
18
• Bond strength:- Only on intact cores
o 70F, zero normal stress
- Run ono Top surface to bottom surfaceo Bottom surface to binder
- Performance based on NCAT Report 12-04
- Performance: guillotine bond strengtho Good: >100psio Medium: 50 – 100psio Poor: ≤ 50psi
Layer debondingGreen good, , red poor
19
• In general, poor performing sections had higher percentages of debonded lifts
• Many poor sections had much lower replicates for bond strength
Bond strengthGreen good, , red poor
20
• Results were mixed
• If a core was intact, regardless of pavement performance, bond strength should be decent
With these mixed results, a new factor is introduced combining debonding percentage and bond strength
Bond strength factorGreen good, , red poor
21
• Multiply bond strength by total decimal of bonded cores (both S2/S1 and S1/B3)
• Performance (psi)- Good > 40- Medium 20-40- Poor < 20
Analysis focused on the following
• Structural adequacy• In-place air voids• Moisture damage• Lack of bond strength• Mix properties
- Lab mix design- Field acceptance
22
• Focused on four properties:- Optimal asphalt content- Voids in Mineral Aggregate (VMA) (for12.5mm NMAS,
>14% per AHTD)- Dust – asphalt content (0.6 – 1.2 per AHTD)- Retained stability (>80% per AHTD)
• Missing three “good” and one “poor” section- G1, G2, G3, P4
• Nmax = 205 for all mixtures- Per AASHTO R 35-15, ESALs > 30 million- Ninit = 9, Ndes = 125, Nmax = 205
Mix design
23
Mix Design – no results out of specification
24However, data is not complete
Three recommendations for ArDOT
25
• Improve moisture susceptibility testing procedures- Move from retained stability to AASHTO T283
• Examine the mix design requirement to ensure adequate air voids are obtained after trafficking- Includes air void requirements, VMA, number of
gyrations during mix design- These could increase optimal asphalt content
• Review cleaning inspection of roadways and application of tack coat specifications- Consider incorporating a field test to measure tack rate
and/or coverage
Summary
• Structural adequacy – not a problem• In-place air voids – potentially part of the problem• Moisture damage – potentially part of the problem• Lack of bond strength – potentially part of the
problem• Mix properties – potentially part of the problem,
need more information- Binder data supports mixture data findings
26
ArDOT recommendations: change moisture testing, examine mix design requirements, and review specifications
27
Additional resources• Yang, S., Braham, A., Underwood, S., Hanz, A., Reinke,
G. “Correlating Field Performance to Laboratory Dynamic Modulus from Indirect Tension and Torsion Bar,” Road Materials and Pavement Design, Vol. 18, Issue S1, January 2017, pp. 104-127.
• Braham, A., Aschenbrener, T., Hossain, Z. “Forensic Investigation of Ten Asphalt Interstate Pavements with Varying Performance in Arkansas,” Journal of Transportation Engineering, Part B: Pavements, June2018, Vol. 144, Issue 2.
Moisture Damage in Asphalt Pavements: Forensic Analyses and Research Needs
Cost/Benefit Analysis of Antistrip Additives in HMA
AcknowledgmentsDon Christensen, Advanced Asphalt
Technologies, LLCDennis Morian and William Wang,
Qualtiy Engineering Solutions, Inc.Neal Fannin, Garth Bridenbaugh,
Heather Heslop and others of PennDOTProducers who participated in surveysReport FHWA-PA-2015-004-110204
Today’s PresentationBased on situation in PennsylvaniaResearch completed in 2015Emphasis in this talk not on details of
laboratory testing program but general issues and benefit/cost analysisLife cycle cost analysis (LCCA)Benefit/cost analysis (BCA) and
Conclusions
Asphalt pavements and moisture sensitivity in PennsylvaniaPennsylvania has a severe climate: wet
with many freeze-thaw cyclesA mix of aggregates, some susceptible
to moisture damage, some notPavements for heavier traffic levels
require varying amounts of aggregates with higher skid resistance levels (SRLs)
Asphalt pavements and moisture sensitivity in PennsylvaniaAggregates with high SRLs tend to be
moisture susceptibleAntistrip usage dependent on results of
AASHTO T 283 testingBetween 2003 and 2014, PennDOT
used a low-saturation Lottman method that produced saturation levels of only 30 to 50 %.
Significance of Moisture Resistance Testing ErrorsType I error
– “Good” mixes that fail testing– Cost of error is unnecessary use of
antistrip—relatively minorType II error
– “Bad” mixes that pass testing– Cost of error is high maintenance,
premature failure--expensive
Accuracy of High SaturationT 283 Testing: Overall, Including Results of From Similar Research
Type I error rate: 6 %Type II error rate
– 23 % for highly susceptible aggregates– 62 % for moderately susceptible
aggregates
Accuracy of Low SaturationT 283 Testing
Type I error rate: 0 %Type II error rate: 100 %
LIFE CYCLE COST ANALYSIS…
IC PMCiPMCj
PMCn
NPV=?
0 1 2 3 n
EUAC=?
−+
+=
1)1()1(
n
n
iiNPVEUAC
k
n
kk i
PMCICNPV)1(
11 +
+= ∑=
Net present value (NPV) and estimated uniform annual cost (EUAC)
Fixed Input Values
Variable ValueDiscount Rate* 2%
Analysis Period (Years) 24
Assumed Project Length (Mile) 1
Lane Width (Feet) 12
HMA Density (lb/sy/in) 110
Asphalt Adjustment Multiplier (AAM)*(values from ECMS)
1.12
Performance Assumptions w/ ExperimentalDesign: Performance Cycle Assumptions
GeneralPerformanceAssumption forSusceptible Mixes Antistrip
Resistant Mixes
Performance Cycles:
No. Duration Total
RealisticWithout 2 12 24
With N/A N/A N/A
OptimisticWithout 2 12 24
With N/A N/A N/A
Performance Assumptions w/ ExperimentalDesign: Performance Cycle Assumptions
GeneralPerformanceAssumption forSusceptible Mixes Antistrip
Highly Susceptible Mixes
Performance Cycles:
No. Duration Total
RealisticWithout 4 6 24
With 3 8 24
OptimisticWithout 3 8 24
With 2 12 24
Performance Assumptions w/ ExperimentalDesign: Performance Cycle Assumptions
GeneralPerformanceAssumption forSusceptible Mixes Antistrip
Moderately Susceptible Mixes
Performance Cycles:
No. Duration Total
RealisticWithout 3 8 24
With 2 12 24
OptimisticWithout 2 12 24
With 2 12 24
LCCA Results for Realistic Scenario
Comparison of EAUC (Including User Cost) among Realistic Scenarios
$0
$5,000
$10,000
$15,000
$20,000
$25,000
$30,000
$35,000
$40,000
$45,000EU
AC
($/L
ane-
mi.)
SRL-M $14,647 $27,804 $22,670 $21,977 $14,696
SRL-G $15,728 $29,793 $24,172 $23,479 $15,777
SRL-H $16,757 $31,606 $25,644 $24,951 $16,806
SRL-E $21,466 $39,863 $31,998 $31,305 $21,515
C RHN RHS RMN RMS
C= no moisture damage; RHN= highly susceptible mix, no antistrip; RHS = highly susceptible mix with antistrip; RMN = moderately susceptible mix, no antistrip; RMS = moderately susceptible mix with antistrip.
BENEFIT/COST ANALYSIS AND CONCLUSIONS
Benefit/Cost AnalysisAnalyze all costs and benefits of a
possible decisionUse net present value (NPV) or
equivalent annual uniform cost (EAUC)B/C = 1 at break evenB/C > 1 indicates economical outcomeB/C < 1 indicates uneconomical
BCA of Moisture Resistance Testing and Antistrip UsageCost = cost of testing and cost of AS;
relatively smallBenefit = increased pavement life, lower
maintenance costsCBA must consider costs, benefits and
accuracy of testing
BCA Sensitivity Analysis
Discount rateTraffic growth ratePercentage of susceptible aggregatesRelative performance of poor
aggregates Improvement resulting from antistripMandatory vs. conditional AS usageWith and without user delay costs
Final Estimates of Resistant/Susceptible Aggregates70 % resistant
– 80 % limestone/dolomite/other resistant aggregates
– Reduced by blending for skid resistance20 % moderately susceptible, other
crushed stone and aggregate blends10 % highly susceptible, all crushed
gravel, some other aggregates
Other AssumptionsPercentage of susceptible aggregates:
20 % (10 % and 40 %); 50/50 split between highly and moderately susceptible (conservative)4 million tons per year subject to
moisture resistance testingAverage thickness 1.75 in, 12 ft. width1,500 tests per year at $320 per test
B/C Ratio, w/o Delay Costs, Realistic Scenario, Discount Rates
Benefit/Cost vs. Overall Savings
Benefit/cost ratio should only be used to determine whether or not a given course of action is economical—B/C ratios should not be used to decide among viable optionsAmong viable options (B/C >> 1),
selection should be based on net savings or similar criteria
Yearly Saving from Mandatory Antistrip Usage, without User Delay Costs
Scenario/Savings% Susceptible Aggregates
40 20 10Realistic/Conditional $8,000,000 $4,000,000 $1,900,000Realistic/Mandatory $14,700,000 $7,200,000 $3,400,000Savings Mand./Cond. $6,700,000 $3,200,000 $1,500,000Percent 6.0 3.2 1.6Optimistic/Conditional $6,600,000 $3,300,000 $1,600,000
Optimistic/Mandatory $8,500,000 $4,100,000 $1,800,000Savings Mand./Cond. $1,800,000 $800,000 $300,000Percent 1.9 0.8 0.3
Yearly Savings with Mandatory Antistrip Usage, with User Delay Costs
Scenario/Savings% Susceptible Aggregates
40 20 10Realistic/Conditional $9,100,000 $4,600,000 $2,200,000Realistic/Mandatory $16,700,000 $8,200,000 $3,900,000Savings Mand./Cond. $7,500,000 $3,600,000 $1,700,000Percent 5.9 3.2 1.6Optimistic/Conditional $7,300,000 $3,600,000 $1,800,000
Optimistic/Mandatory $9,400,000 $4,500,000 $2,100,000Savings Mand./Cond. $2,000,000 $900,000 $300,000Percent 1.8 0.8 0.3
PennDOT policy changesPennDOT abandoned the low-
saturation Lottman method in October 2014 and returned to the high-saturation procedureDistrict material engineers may require
antistrip in mixes known to be moisture susceptible, even if they pass moisture resistance testing without antistrip
Conclusions
B/C of low saturation testing is zeroB/C of high saturation testing with AS
usage always much greater than oneB/C for both conditional and mandatory
AS usage both much greater than one
ConclusionsMandatory usage of AS appears to be a
more economical approach than AS usage conditional on test outcome– Cost of AS very low relative to cost of
moisture damage– Mandatory usage avoids high cost of type
II errors (susceptible mixes pass test)
Needs for further research
Liquid antistrip additives may not be as effective in actual pavements as in laboratory testingSome evidence suggests that hydrated
lime is much more effective in practiceEffect of mix/pavement permeability on
moisture damage
Research need gaps
Moisture Damage in Asphalt Pavements
Silvia CaroTRB Webinar -October 2018
Methodology
Two main sources of information were used:
183 published papers in the last 7 years in some of the most relevant international indexed journals in the area of pavement engineering.
Survey to US DOTs (39% response rate) and researchers (18 experts).
1
2
Trends in moisture damage research
Papers in moisture damage published per year
3 46
86 6
8
16 1519
33
21
42
0
5
10
15
20
25
30
35
40
45
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
Num
bero
f pap
ers
Year
56%
20%
4% 2% 3%6%
2%8%
0%
10%
20%
30%
40%
50%
60%
70%
HMA
WM
A
CMA
RAP
or R
AS
Mas
tic
Bitu
men
/Agg
reg
ate
Asph
alt
Oth
er
Perc
enta
ge o
f pap
ers
Papers published per type of material
Trends in moisture damage research
Papers per scale of study
Macro79%
Micro18%
Nano1%
Other 2%
Trends in moisture damage research
Trends in moisture damage research
0
20
40
60
80
100
120
140
Num
ber o
f pub
lishe
d pa
pers
Netherlands Thailand India Lithuania Australia
Canada Malaysia China Spain USA
Iran United Kingdom Pakistan Normay Italy
South Africa Qatar UAE Turkey Sweden
Chile Colombia Korea Japan Costa Rica
Singapore Brazil Bahrain
ColombiaMalaysia
Canada
Italy
CostaRica
SouthAfricaPakistan
Sweden
USA
China
UK
Spain
Iran KoreaTurkey
IndiaNetherl.
Papers per country
Papers per institution
Trends in moisture damage research
0
5
10
15
20
Num
ber o
f Pap
ers
Nottingham Leicester Scott Wilson LtdLiverpool De Montfort University Amirkabir University of TechnologyShahid Rajaee Teacher Training University Babol Noshirvani University of Technology Iran University of Science and TechnologyUniversity of Tehran Texas A&M Arizona State UniversityArgon National Laboratory Clemson University IndependantIowa Department of Transportation Iowa State University Louisiana State UniversityLouisiana Technical University Michigan Technological University Mississippi State UniversityNorth Carolina State University Oregon State University Paragon Technical ServicesPennsylvania State University Rutgers University South Dakota State UniversityTemple University Texas Transportation Institute The American University in CairoUniversity of California University of Illinois University of Louisiana LaffayetteUniversity of Kansas University of Maryland University of MinnesotaUniversity of Nebraska-Lincoln University of Nevada University of New HampshireUniversity of New Jersey University of New Mexico University of MassachusettsUniversity of Oklahoma University of Texas at Austin University of Winsconsin-MadisonUniversity of Wyoming US Army engineer research and development center US Federal Highway AdministrationVanderbilt University Washington State University Western Research InstituteWorcester Polytechnic Institute Laboratorio de Ingenieria de la Construcción Universidad de CoruñaUniversity of Granada Universidad de Huelva Hunan UniversityNanjing University of Aeronatutics and Astronautics Tongji University Huazhong University of Science and TechnologySouthwest Jiaotong University Shandong University Northeast Forestry UniversityHarbin Institute of Techonology China University of Petroleum Wuhan University of TechnologyChina Academy of Engineering Physics Southeast University Dessign And Research Insitute
Texas A&MNottingham
Amirkabir Wuham UTWisconsin
TU Delft
New Mexico
Nebraska
Michigan
Louisiana
IranUST
IIT Bombay U. AndesClem-
son NCST
Nevada
UT Austin
SainsMalaysia
Harbin ITTongjiKansas
Kyung Hee
DOTs perception on moisture damage
Survey to DOTs
Is moisture damage considered a major issue affecting the durability of flexible pavements in your State?
Q1
57%43%
YesNo
DOTs perception on moisture damage
Survey to DOTs
Q2 Does your DOT has/or had any type of specification for preventing/controlling moisture damage? Which one?
16
1 1
3
0
2
4
6
8
10
12
14
16
18
TSR-AASHTO T283 Hamburg Wheel Test Various None
Num
ber o
f sta
tes
DOTs perception on moisture damage
Survey to DOTs
Q3 Does your DOT require the use antistripping agents? If yes, which type?
9
6
5
2
2
0 2 4 6 8 10 12
Number of States
Addi
tive
Discretion contractor
No need
Liquid antistriping
Hydrated lime
Other types
DOTs perception on moisture damage
Survey to DOTs
Q4 Which are the main topics that, based on the experience in your State, require immediate attention:
1. Understanding the role and efficiency of certain additives used in asphalt mixtures moisture damage (e.g. aggregate treatments, oil additive treatments, impact of ARAs, etc.).
2. A better and more reliable characterization test.
3. Moisture damage of mixtures with RAP/RAS.
4. Methods to improve material selection (e.g. aggregates) to prevent moisture damage.
5. Correlation between lab characterization and field performance.
Researchers experience and perception on moisture damage
Survey to researchers
Q1 Your experience working on moisture damage has been mainly focused on:
Researchers experience and perception on moisture damage
Q2 Your experience working on moisture damage has been mainly focused on which type of mixtures?
Survey to researchers
Researchers experience and perception on moisture damage
Q3 From your personal point of view, what is the best test currently available for quantifying moisture susceptibility of asphalt mixtures (if any)?
29%
41%
24%
6%
AASHTO T283 (or related)
HWTNone
SATS
Survey to researchers
Researchers experience and perception on moisture damage
Q4 Which are the topics in this area that require our attention:
1. Relationship between moisture damage and oxidation.2. Test methods and characterization of moisture susceptibility
of specific mixtures.3. Relationship between lab characterization and field
performance.4. Considerations to include moisture damage as part of current
mechanistic-based pavement design methodologies.5. Adhesion and interface issues.6. Fundamental mechanisms and processes.7. Others.
Survey to researchers
Summary
Moisture damage continues being a topic of interest in pavement engineering.
Several DOTs seem to have implemented procedures to prevent moisture damage. However, there are new challenges regarding the use of new and/or recycled materials and the increasing offer of new additives in the market.
Main research gaps:
• Tests procedures to characterize moisture susceptibility, • coupled environmental phenomena, and• fundamental mechanisms driven this degradation process.
Today’s Participants• Tim Aschenbrener, Federal Highway Administration,
[email protected]• Silvia Caro, Universidad de Los Andes,
[email protected]• Derek Nener-Plante, Maine Department of Transportation,
[email protected]• Andrew Braham, University of Arkansas, [email protected]• Donald Christensen, Advanced Asphalt Technologies LLC,
Advanced Asphalt Technologies, LLC
Panelists Presentations
http://onlinepubs.trb.org/onlinepubs/webinars/181031.pdf
After the webinar, you will receive a follow-up email containing a link to the recording
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