continuous deflection for comprehensive pavement...
TRANSCRIPT
Continuous Deflection for Comprehensive Pavement Assessments
Thursday, May 30, 20191:00-3:00 PM ET
TRANSPORTATION RESEARCH BOARD
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requirements of the Registered Continuing Education Providers Program.
Credit earned on completion of this program will be reported to RCEP. A
certificate of completion will be issued to participants that have registered
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
To discuss the applications of continuous pavement deflection.
Learning Objectives
At the end of this webinar, you will be able to:
• Describe the limitations of traditional assessments
• Identify continuous deflection capabilities• Describe how other agencies are applying
results• List the benefits and advantages of
comprehensive assessment
Comprehensive Pavement Assessments Using Continuous DeflectionTRANSPORTATION RESEARCH BOARD WEBINAR1:00 PM – 2:30 PMTHURSDAY, MAY 30, 2019
Agenda
1. Introduction 2. Pavement assessment3. Continuous deflection technology4. Applications to date5. Benefits to agencies6. Questions & answers
May 30, 2019 Comprehensive Pavement Assessments using Continuous Deflection 2
1. Introduction
Dr. Nadarajah Sivaneswaran (Siva), P.E.Federal Highway Administration
2. Pavement Assessment
Dr. Gerardo Flintsch, P.E.Center for Sustainable Transportation Infrastructure,
Virginia Tech
Introduction
Pavement Management – A key Asset Management business process
• Pavements are the most “valuable” asset in terms of patrimonial value
• Impact safety, user costs, noise generation, …Structural condition evaluation and monitoring:
– A fundamental block of an efficient pavement management program
Why do we “manage” our pavements?
To preserve our infrastructure value– Key component of the asset management
To develop “optimum” pavement preservation and renewal programs– Better Use of Available Resources
To provide a level of service that the user considers appropriate– Maintain a State of
Good Repair
State of the Practice on Pavement Condition Data
Surface condition– Easy to obtain– Collected for the road network– Used to assess the overall condition– Implemented in a PMS
Structural capacity/condition– Hard to obtain– Seldom collected for the network– Used to design pavement treatment
7
Flintsch, G.W., and McGhee, K.K., NCHRP Synthesis 401 - Quality Management of Pavement Condition Data Collection, Transport Research Board, NAS-NRC,2009, Washington, DC, 155 pp. http://onlinepubs.trb.org/onlinepubs/nchrp/nchrp_syn_401.pdf.
Pavement Condition “Quality” Measures & Performance Indicators
Service and User Perception
Physical Condition
Structural Integrity / Load-Carrying Capacity
Safety andSufficiency
Environmental Impact
Serviceability (PSI, IRI)
Distress(PCI)
Deflection(FWD)
Friction (FN)/ Macrotexture
Tire/PavementNoise
Is cracking a good indicator of structural integrity?
150 160 170 180 190 200 210 220 2300
0.5
1
1.5
2
Pavement Condition on I81 South
Milepost
SCI 30
0 (mil)
150 160 170 180 190 200 210 220 2300
20
40
60
80
100
Fatig
ue C
rack
ing
Seve
rity
1 (f
t 2 )
Structural Condition TSDFunctional Condition PMS
SCI300vs Cracking
Destructive– Coring, trenches, material testing, etc.– Time-consuming, expensive, and
degrade pavement Non Destructive Evaluations (NDE)
– Deflection Measuring Equipment– Ground Penetrating Radar– Infrared Thermography– …
“Traditional” Structural Capacity Assessment
Deflection Measurement Technologies “Static” Measurement
Devices
Moving Devices with Stationary Measurement Equipment
Moving Measurement Vehicles with Non-Stationary Measurement Apparatus
3. Continuous Deflection Technology
Dr. Gerardo Flintsch, P.E.Center for Sustainable Transportation Infrastructure,
Virginia Tech
Continuous Deflection in the US
13Advancing Transportation Through Innovation
Development
Assessment
Evaluation
Demonstration
Implementation
Several State Efforts
Idaho
Virginia
Louisiana
Nationwide
SHRP 2 R06 (F) Assessment of Continuous Pavement Deflection Measuring Technologies
0
2
4
6
8
10
12
14
105 110 115 120 125 130 135 140
RWD
Defle
ctio
n (m
ils)
Mile Marker
RWD Deflection (0.1 mile avegrage) Moving Average
Sectioning (based on last resurfacing)
RWD
0.000
0.100
0.200
0.300
0.400
0.500
0.600
0.700
0.800
0.900
1.000
0 500 1000 1500 2000 2500 3000 3500 4000
Defle
ctio
n Sl
ope
[mm
/m]
Chainage [m]
10m averages
100m averages
TSD
http://onlinepubs.trb.org/onlinepubs/shrp2/SHRP2prepubR06F.pdf
Network Level Pavement Structural Evaluation
Assess and evaluate capability of traffic speed deflection-related devices for pavement structural evaluation at network level
Develop methodologies for enabling use of devices in pavement management
https://www.fhwa.dot.gov/publications/research/infrastructure/pavements/15074/15074.pdf.
Demonstration of Network Level Pavement Structural Evaluation with Traffic Speed Deflectometer
Objective: To assess the feasibility of and demonstrate the use of the TSD for network level structural evaluation for use in the participating agencies’ pavement management application and decision making
Partners: FHWA, CA , GA , ID , IL , NV , NY , PA , SC , VATransportation Pooled Fund Study TPF-5(282)
ESC Inc. Greenwood Engineering VTTI TRL
http://www.pooledfund.org/Details/Study/518
Traffic Speed Deflectometer
SCI300
Data Collection & Processing
Pavement deflection velocityLaser Doppler
Pavement deflectionIntegration of deflection slopes
Temperature corr. deflectionsStrain-based procedure
Deflection IndicesSCI300, DSI, SNeff,
Pavement deflection slopeVv / Vh
Structural Indices
SCI12 (SCI300):– D0 – D12
DSI4-12:– D4 – D12
SNeff:– SIP = D0 – D1.5Hp
– SNeff = k1 * SIPk2 * (Hp)k3
TPF-5(282) Main Products
Approaches for classifying the structural condition• Mechanistic approach based on tensile strain at the asphalt
bottom• Percentile from the cumulative distribution of SCI300• SNeff derived from TSD data
Framework to incorporate the TSD-measured structural condition within a SHA’s PMS • Structural condition can be use to enhance treatment selection
20
RAPTOR
May 30, 2019 Continuous Deflection for Comprehensive Pavement Assessments 21
Network Level Pavement Structural Testing with the Traffic Speed Deflectometer (TSD) in VirginiaPilot Implementation Collected continuous deflections for the Interstate and
primary roads
Enhanced project selection decision tree
Pavement Surface
Distresses
Fatigue Cracking
Transverse Cracking
Rutting
Patching
…….
Condition Index
Decision Process
(Matrices)
Treatment Selection
Augmented Decision Process
Structural Condition
Final Treatment Selection
Do Nothing
Preventive Maintenance
Corrective Maintenance
Rehabilitation
Reconstruction
Fair Structural Condition
4. Applications to Date
Dr. Brian Diefenderfer, P.E.Virginia Transportation Research Council
Use of Network Structural Testing
Scoping network level needs:
– Overall health of the pavement
– Structural index to use in PMS
– Remaining structural life– Resource allocations
Screening sections:– Strong vs. weak sections– Heavy treatment vs.
preservation treatment– Need more detailed
evaluation
24
VDOT Enhanced PMS Decision Trees
VTRC Report 13-R9
Correlation Between Structural and Functional Condition
DistressSpearman Rank
Coefficient
Center Deflection
LDR -0.1444NDR -0.1285CCI -0.1254IRI 0.0597
Rut Depth 0.0319Total Alligator
Cracking0.1382
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
0 20 40 60 80 100
FWD
Cent
er D
efle
ctio
n (m
ils)
Load Related Distresses (LDR)
I-81 South; Functional Vs. Structural Parameters
VTRC Report 13-R9
Impact of Structural Capacity
0 2 4 6 8 1040
50
60
70
80
90
100
Expected Life (Years)
CC
I
Pavement in Bad Structural ConditionPavement in Good Structural Condition
The pavement that isin bad structuralcondition deterioratesfaster
−−=tcbaetCCI
1ln*100)(
Poor structural condition deteriorates faster
Structural Health Index VTRC Report 13-R9, Structural index using FWD data collected at the network-level Modified SCI (MSI)→ The SCI concept was introduced by the Texas DOT for network-level analysis
→ MSI was proposed in 2012 as a modified version of the SCI
→ Simplification of the 1993 AASHTO Overlay Design Method→ Based on deflection, traffic level, and calculated Mr
𝑆𝑆𝑆𝑆𝑆𝑆 =𝑆𝑆𝑁𝑁𝑒𝑒𝑒𝑒𝑒𝑒𝑆𝑆𝑁𝑁𝑟𝑟𝑒𝑒𝑟𝑟
𝑀𝑀𝑆𝑆𝑆𝑆 =0.4728 ∗ 𝐷𝐷0 − 𝐷𝐷1.5𝐻𝐻𝐻𝐻
−0.4810 ∗ 𝐻𝐻𝑝𝑝0.7581
0.05716 ∗ (log(𝐸𝐸𝑆𝑆𝐸𝐸𝐸𝐸) − 2.32 ∗ log Mr + 9.07605 2.36777)
Performance and Cost Differences
0
2
4
6
8
10
12
0 0.25 0.5 0.75 1 1.25 1.5
Expe
cted
Ser
vice
Life
(Yea
rs)
MSI
Expected Life of CM Treatment
$0.00
$0.20
$0.40
$0.60
$0.80
$1.00
$1.20
$1.40
$1.60
0 0.25 0.5 0.75 1 1.25 1.5
Expe
cted
Cos
t per
Mile
(Mill
ions
)MSI
Expected Cost of CM Treatments - 25 Year Service
Expected Cost
Rounded Costs
5x increase in cost
Transitional Research
FWD to traffic speed deflection devices (TSDDs)
FHWA study, 2011 & SHRP2 study, 2013– Identified several TSDDs
FHWA study, 2012-2015 & TPF-5(282), 2013-2017– Compared vehicle-measured pavement deflection with embedded
sensors– Compared qualitative ranking of structural condition with FWD– Identified analysis parameters
TPF-5(282) Data Example
TSDD
Implementation Examples
Idaho – Corridor management
• Network structural info with ME performance predictions• Estimate future maintenance schedules
– Planned versus reactive maintenance
Virginia– Previous augmented PMS decision trees
• Replacing FWD with TSDD info
TPF-5(282) Findings
Short- and long-term repeatability is good– More work needed for temperature correction
TSD and FWD followed similar trends– But not a one-to-one replacement as expected
Little relationship between TSD results and PMS surface condition– Shows need for structural testing
2017 Testing in Virginia
4,000+ miles of testing on interstate and primary routes
Study impact on PMS results by including TSDD-based structural response
Deflection indices, rutting, ride quality, cracking, pavement and roadway images, cross slope
VDOT 2017, Remaining Work
Identify structurally strong and weak sections – Compare to PMS decision making and rehab history– Compare to previous structural data (where available)
Determine ranges of calculated indices that identify strong versus weak structural condition– Structural sufficiency vs design – Similar budget output from PMS– Combination?
deflection
thickness
cracking
rutting and IRI
Why a sudden onset of cracking?
Pooled Fund Study, 2018-2021
TPF 5(385), Pavement Structural Evaluation with Traffic Speed Deflection Devices
Agency partners– Arkansas, FHWA, Georgia, Idaho, Illinois, Indiana, Kansas, Louisiana,
Michigan, Minnesota, Mississippi, North Carolina, New Mexico, Oklahoma, Pennsylvania, South Carolina, Tennessee, Texas, Virginia, Vermont, West Virginia
Pooled Fund Study Objectives/Scope
Provide means to conduct demonstration testing– ARRB Group TSD & Dynatest RAPTOR
Develop specifications for data collection and guidelines for PMS application
Demonstrate– How to use data to support project level decision-making– Costs (and any savings) through case studies
Conduct workshops and prepare training
Pooled Fund Study Commitment LevelsOption 1
– Participation in the study for one agency rep (no testing) = $15,000 / year
Option 2a– Option 1 plus one day of testing on agency designated routes (~100-200
miles) = $45,000 / year
Option 2b– Option 2a plus additional days of testing = $32,000 / day / year
Pooled Fund Study Status
Project stated October 2018
Working with agencies to conduct testing– Agency designated routes
2019 testing completed for 6 of 21 agencies– Remainder are in planning phases
Open to adding additional agency partners
5. Benefits to Agencies
Dr. Brian Diefenderfer, P.E.Virginia Transportation Research Council
Benefits
Pavement rehabilitation decision making– More complete information to
make better decisions– Multi-billion dollar implications
Benefits to Agencies
Allow realistic production for network-level structural testing– Significant portions of a network can be covered daily– Include structural properties in PMS decision-making
All this with…– Increased operator and public safety– Continuous (nearly) rather than discrete measurements
Segment 1Segment 2
Virginia Example #1
Segment 3
Virginia Example #2
VDOT division investigating corridor widening project– About 85 directional miles
Initial assumption was to reconstruct entire alignment– Combined use of FWD and TSDD data – Showed that about 65% was structurally adequate
Cost avoidance in the hundreds of millions of dollars
6. Questions and Answers
Dr. Nadarajah Sivaneswaran (Siva), P.E.Federal Highway Administration
Today’s Speakers• Nadarajah Sivaneswaran, Federal
Highway Administration, [email protected]
• Brian Diefenderfer, Virginia Department of Transportation, [email protected]
• Gerardo Flintsch, Virginia Tech, [email protected]
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