pavement vehicle interactions – does it matter for virginia? franz-josef ulm, mehdi akbarian,...
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Pavement Vehicle Interactions – Does it Matter for Virginia?
Franz-Josef Ulm, Mehdi Akbarian, Arghavan Louhghalam
ACPA. Virginia Concrete Conference
March 6, 2014
With the support of the VDOT Team – Thank YOU!
Slide 2
Motivation: Carbon Management
Pavement design and performance:– Fuel saving– Cost saving– GHG reduction
• Strategy for reducing air pollution!
non profit support group for the Route 29 Bypass
Slide 3
OUTLINE3
• This is not about Concrete vs. Asphalt, this is about unleashing opportunities for Greenhouse Gas savings
• Pavement-Vehicle Interaction: – Roughness/ Vehicle Dissipation– Deflection/ Pavement Dissipation
• Data Application:–US Network–VA Network
• Carbon Management: how to move forward
Slide 4
• Force Distribution in a passenger car vs. speed as a percentage of available power output (Beuving et al., 2004; cited in Pouget et al. 2012)
Context: Rolling Resistance
Due to PVIs: Texture, Roughness and Deflection
Slide 5
• Pavement Texture: Tire industry. Critical for Safety. Tire-Pavement contact area.
• Roughness/Smoothness*: – Absolute Value = Vehicle dependent.– Evolution in Time: Material Specific
• Deflection/Dissipation Induced PVI**:– Critical Importance of Pavement Design Parameters:
Stiffness, Thickness matters! – Speed and Temperature Dependent, specifically for inter-city
pavement systems
Key Drivers of Rolling Resistance
*Zaabar, I., Chatti, K. 2010. Calibration of HDM-4 Models for Estimating the Effect of Pavement Roughness on Fuel Consumption for U.S. Conditions. Transportation Research Record: Journal of the Transportation Research Board, No. 2155. Pages 105-116.** Akbarian M., Moeini S.S., Ulm F-J, Nazzal M. 2012. Mechanistic Approach to Pavement-Vehicle Interaction and Its Impact on Life-Cycle Assessment. Transportation Research Record: Journal of the Transportation Research Board, No. 2306. Pages 171-179.
Slide 6
ROUGHNESS / IRI: Dissipated Energy
• Quarter-Car Model*• Mechanistic/PSD**: with:
IRI
• HDM-4 Model***:
IRI measured at c=80 km/h = 50 mph= Damping of Suspension System (Vehicle Specific)
𝒛 (𝒕) 𝐶𝑆
(*) Sayers et al. (1986). World Bank Technical paper 46
(**) Sun et al. (2001). J. Transp. Engrg., 127(2), 105-111.(***) Zaabar I., Chatti K. (2010) TRB, No. 2155, 105-116.
VehicleSpecific
ReferenceIRI-Value
VEHICLE–SPECIFIC ENERGY DISSIPATION & EXCESS FUEL CONSUMPTION
Slide 7
ROUGHNESS: HDM-4 MODEL
• Zaaber & Chatti (2010)
• Input:– Measured IRI (t)– Reference IRI, – Vehicle Type– Traffic Volume (AADT, AADTT)– Truck Traffic Distribution
• Output:– Excess Fuel Consumption due to
Roughness– For vehicle type and total
*Zaabar, I., Chatti, K. 2010. Calibration of HDM-4 Models for Estimating the Effect of Pavement Roughness on Fuel Consumption for U.S. Conditions. Transportation Research Record: Journal of the Transportation Research Board, No. 2155. Pages 105-116.
𝛿𝐸=% 𝐸0 ⟨ IRI − 𝐼𝑅𝐼 0 ⟩
Slide 8
MIT Model Gen II: Viscoelastic Top Layer
P
k
E = htEs s
c
Speed Dependence
Temperature dependence
Relaxation Time
– Bituminous Materials* – Cementitious Materials**:
* Pouget et al. (2012); William, Landel, Ferry (1980) ** Bazant (1995)
𝒄𝒄𝒓=𝓁𝑠(𝑘 /𝑚)1/2Winkler Length
Consideration of Top-Layer Viscoelastic behavior, including temperature shift factor:
Slide 90 10 20 30 40 50 60 70
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
Pouget et al. (2012)MIT Model
TEMPERATURE [Deg.C]
DISS
IPAT
ED E
NER
GY [M
J/km
]
c= 50 km/h
0 10 20 30 40 50 60 700
0.2
0.4
0.6
0.8
1
1.2
1.4
Pouget et al. (2012)MIT Model
TEMPERATURE [Deg.C]
DISS
IPAT
ED E
NER
GY [M
J/km
]
c= 100 km/h
Calibration/Validation | Asphalt Lit. Data
• Model-Based Simulations
𝛿𝐸=𝑐𝑐𝑟
𝑐×
𝑃2
𝑏𝑘𝓁𝑠2𝐹 ( 𝑐𝑐𝑐𝑟
;𝜁=𝝉 (𝑻 )𝑐𝑐𝑟𝓁𝑠
) Vehicle speed ton truck (distribution of loads according to HS 20-44) m (lane width) 40,264 MPa, 35 MPa/m, 0.22 m s
𝜏 (𝑇 )=𝜏0 (𝑇 0 )×𝑎𝑇 (𝑇 )
Calibration c=100 km/h
Validation c=50 km/h
Slide 10
0 20 40 60 80 100 1200
0.05
0.1
0.15
0.2
0.25
0.3
0.35
SPEED [km/h]
DIS
SIP
AT
ED
EN
ER
GY
[M
J/k
m]
New Feature: Temperature and Speed Dependence
(Example taken from Pouget et al. (2012)
Gen I
50 Deg. F
68 Deg. F
Slide 11
Can we do better? – Yes, we can!
Pavement RoughnessPavement Deflection
Structure and Material
MEPDG2011 MIT-Model
PVI Impact
Slide 12
LCA “plus”: MOVING LCA IN THE DESIGN SPACE
MEPDG
StructurallySound Design
INPUT:- Structure- Materials- Traffic- Climate- Design
Criteria
LCA/LCCAEmbodied + Use
OUTPUT:- E(t)- IRI(t)- Maintenance- Traffic-evolution
SustainableDesign
OUTPUT:- Fuel Con.- GHG- Costs
OUTPUT:- Comparative
Design- Design
Alternatives
Slide 13
Network ApplicationUS and VA
Slide 14
FHWA/LTPP General Pavement Study sections (GPS)
Data:Roughness• IRI (Year)• Traffic• Location• Pavement typeDeflection:• Top layer modulus E• Subgrade modulus k• Top layer thickness h• Other layer properties
GPS1: AC on Granular Base
GPS2: AC on Bound Base
GPS3: Jointed Plain CP (JPCP)
GPS4: Jointed Reinforced CP (JRCP)
GPS5: Continuously Reinf. CP (CRCP)
GPS6: AC Overlay of AC Pavement
GPS7: AC Overlay of PCC
GPS9: PCC Overlay of PCC
AC ComPCC
Slide 15
VA Interstate: Road Classification
Pavement type analyzed
Type Lane-mile Center-mileAsphalt (BIT) 3,131 1,416Concrete (CRCP, JRCP)Composite (BOC, BOJ)
4901,221
174459
Total 4,841 2,05065%8%
18%
3%7%
BITBOCBOJCRCPJRCP
VA Label Type LTPP Equivalent
BIT Bituminous GPS 1,2
JRCP Jointed reinforced CP GPS 4
CRCP Continuously reinforced CP GPS 5
BOJ Bituminous over JPCP GPS 6
BOC Bituminous over CRCP GPS 9
Slide 16
VA Interstate: Data Overview
Data: • 15 interstates, 2 direction• Years: 2007-2013• Section ID• Section milepost• AADT, AADTT• Layer thicknesses• Material properties (2007)• IRI (t)
ACComPCC
Pavement Type
Slide 17
Annual Average Daily Truck Traffic (AADTT)
AADTT
Slide 18
Deflection -Induced PVI
Slide 19
Temperature and Speed Sensitivity: AC in VA
𝛿𝐸=− 𝑃 𝑑𝑤𝑑𝑋
=𝑐𝑐𝑟
𝑐𝑃2
𝑏𝑘𝓁𝑠2×𝐹 ( 𝑐
𝑐𝑐𝑟
;𝜁=𝝉(𝑻 )𝑐𝑐𝑟𝓁𝑠
)Asphalt Concrete (BIT)
Temperature sensitivityone order of magnitude higher dissipation
(T= 50 vs. 65 F)
tons (3 axles); mph; s; VA Interstate database for distributions of of AC
Asphalt Concrete (BIT)
tons (3 axles); ; s
Speed Sensitivityhalf order of magnitude higher dissipation
( vs. 60 mph)
1 100
2
4
6
8
10
12
T=10C/50F
T=20C/65F
Dissipated Energy [MJ/km]
PD
F/1
1 100
2
4
6
8
10
12
c=60 mphc=20 mph
Dissipated Energy [MJ/km]P
DF
/1
Slide 20
Temperature Sensitivity: PCC in VA
𝛿𝐸=− 𝑃 𝑑𝑤𝑑𝑋
=𝑐𝑐𝑟
𝑐𝑃2
𝑏𝑘𝓁𝑠2×𝐹 ( 𝑐
𝑐𝑐𝑟
;𝜁=𝝉(𝑻 )𝑐𝑐𝑟𝓁𝑠
)Concrete (JRCP, CRCP)
Temperature sensitivitySmall!
tons (3 axles); mph; s; VA interstate database for distributions of of PCC
Speed Sensitivity Small
Concrete (JRCP, CRCP)
tons (3 axles); ; s
[For pure comparison, assume same as for asphalt]
0.001 0.01 0.10
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
T=20C/65F
T=10C/50F
Dissipated Energy [MJ/km]
PD
F/1
0.001 0.01 0.1 10
0.5
1
1.5
2
2.5
c=20 mph
c=60 mph
Dissipated Energy [MJ/km]P
DF
/1
Slide 21
Would this matter for VA?
BIT/ACTemperature sensitivity
10 Deg. can entail one order of magnitude of higher energy
dissipation; thus fuel consumption.
Assume: Bit @ 95%. P=37 tons (3 axles); τ0=0.015s Assume: PCC @ 95%. P=37 tons (3 axles); τ0=0.015s
PCCTemperature sensitivity
10 Deg. can entail half order of magnitude of higher energy
dissipation; thus fuel consumption.
* Temp data from National Oceanic and Atmospheric Administration (esrl.noaa.gov)
Order of magnitude difference
Slide 22
VA Network: PVI Deflection – Truck
0.0001 0.001 0.010
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6Bituminous
Excess Fuel Consumption (gal/mile)
PD
F/1
Excess fuel consumption due to PVI deflection is 10 times higher on bituminous pavements
c= 100 km/h=62.6 mph; T= 16 C/61 F
Slide 23
Annual Excess Fuel Consumption: PVI Deflection*2013 data
FC (gallon/mile)
c= 100 km/h=62.6 mph; T= 16 C/61 F
Slide 24
• PVI-model Gen II:– Accounts for the effect of temperature and
vehicle speed on the dissipated energy.– Quantifies asphalt and concrete sensitivity to
speed and temperature.– Requires one material input parameter:
relaxation time. So far, calibrated and validated using literature data. Link with Master Curve.
– Simple to use, easy to calculate fuel consumption in excel spreadsheet; thus for LCA use phase…
Summary | For Discussion
Slide 25
IRI-Induced PVI
Slide 26
IRI: US Network – VA Data Comparison
IRI distribution of Virginia and the US network are very similar.
<60 60-94 95-119 120-144 145-170 171-194 195-220 > 2200
0.1
0.2
0.3
0.4
0.5
0.6
VA Network
US Network
IRI (in/mile)
Fre
qu
en
cy
<60 60-94 95-119 120-144 145-170 171-194 195-220 > 220
0
0.2
0.4
0.6
0.8
1
1.2
VA Network
US Network
Slide 27
VA – Roughness
Asphalt and composite pavements are maintained equally. Not concrete
<60 60-94 95-119 120-144 145-170 171-194 195-220 > 220
0
0.2
0.4
0.6
0.8
1
1.2
Concrete
Asphalt
Composite
<60 60-94 95-119 120-144 145-170 171-194 195-220 > 2200
0.1
0.2
0.3
0.4
0.5
0.6
0.7
VA Concrete
VA Asphalt
VA Composite
IRI (in/mile)
Fre
qu
en
cy
*2013 data
Slide 28
IRI depends on pavement maintenance
MN (2011)
<60 60-94 95-119 120-144 145-170 171-194 195-220 > 220
0
0.2
0.4
0.6
0.8
1
1.2
ConcreteAsphaltComposite
<60 60-94 95-119 120-144 145-170 171-194 195-220 > 220
0
0.2
0.4
0.6
0.8
1
1.2
Concrete
Asphalt
Composite
VA (2013)
Slide 29
Pavement Roughness (IRI)*2013 data
IRI (in/mile)
Slide 30
Excess Fuel Consumption: PVI Roughness*2013 data
FC (gallon/mile)
Slide 31
Annual Expenditure on all Pavements in VA
2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012$0
$50
$100
$150
$200
$250
$300
$350
$400Asphalt Pavement
Concrete Pavement
Year
Pa
ve
me
nt
Ex
pe
nd
itu
re (
Mill
ion
s o
f $
)
Deficient lane miles due to ride quality by pavement type – Interstate
Pavement Type lane-mile (% total) Deficient lane-miles (% total)*AC 3,131 (65%) 157 (46%)PCC 490 (10%) 181 (54%)Total 3,621 (75%) 338 (100%)
Cost aggregated for:- Interstate pavement- Primary pavement- Secondary pavement
Deficient pavement IRI:- Poor: 140-199- Very poor: >200
*VDOT. State of The Pavement 2012. http://www.virginiadot.org/info/resources/State_of_the_Pavement_2012.pdf
Slide 32
• IRI is vehicle specific
• Concrete pavements are under-maintained
• Difference between pavement systems is IRI-development and pavement aging. Data not consistent with national analyses
• Model Development:
Reference in/mile = Political decision
Higher value of reduces the number of roads contributing to excess fuel consumption.
SUMMARY: IRI-induced PVI
𝛿𝐸=% 𝐸0 ⟨ IRI − 𝐼𝑅𝐼 0 ⟩
Slide 33
Total PVI Impact
Slide 34
Network: Annual PVI Truck* – excess FC per mile*2013 data
Impact Reduction through enhanced pavement design and management
BIT BOC BOJ CRCP JRCP0
2000
4000
6000
8000
10000
12000
14000
16000
0
20
40
60
80
100
120
140
160Roughness Deflection
An
nu
al E
xc
es
s F
ue
l Co
ns
um
pti
on
(G
al/m
ile)
An
nu
al E
xc
es
s C
O2
e E
mis
sio
ns
(t
on
s/m
ile)
c= 100 km/h=62.6 mph; T= 16 C/61 F
Slide 35
Network: Annual PVI Truck – Total FC
2007 2008 2009 2010 2011 2012 20130
1,000,000
2,000,000
3,000,000
4,000,000
5,000,000
6,000,000
7,000,000
0
10,000
20,000
30,000
40,000
50,000
60,000
70,000
Annual Truck FC Roughness Annual Truck FC Deflection
Ex
ce
ss
Fu
el C
on
su
mp
tio
n (
Ga
llon
s)
Ex
ce
ss
CO
2e
Em
iss
ion
s (
ton
s)
c= 100 km/h=62.6 mph; T= 16 C/61 F
Slide 36
PVI Total Impact: Roughness and Deflection*2013 data: Trucks
FC (gallon/mile)
c= 100 km/h=62.6 mph; T= 16 C/61 F
Slide 37
CARBON MANAGEMENT = Pavement Performance!
• PVIs contribute highly to pavement induced fuel consumption and GHG emissions
• Concrete pavements not utilized to same performance as in other roadway networks– High deficient lane-miles
– Older pavements
• Room for GHG reduction!
ENGINEERING100%
Moving tire (top view) is on slope= Deflection induced eXtra-Fuel Consumption
Slide 38
CARBON MANAGEMENT = Cost – Benefit!
ECONOMICS = LINGUA FRANCA OF IMPLEMENTATION• LCCA is tool for supporting design
decisions• Analyses typically occur after design
process is complete• Standard practice does not account for
uncertainty• FHWA does not provide guidance on
characterizing inputs and uncertainty
ECONOMICS100%
Slide 39I N V E S T – I N N O VAT E – I N V I G O R AT E - I M P L E M E N T
LCCA VALUE PROPOSITION
• Context: $ 2 Trillion Infra-structure renewal job within tightest budgetary constraints.
• Problem: Volatility of construction materials pricing for a fiscally sound decision making.
• Solution*: A new LCCA methodology with probabilistic cost modeling of pavement projects, so that decision-makers: – Understand the risk of an investment;– Select a design based on risk perspective.
ECONOMICSDecision Makers (local, national,
and beyond)
IMPLEMENTATION@ State Level: Case Study
* Swei, Gregory & Kirchain (2013)
Slide 40
Uncertainty is pervasive in pavement LCCA
Construction Operation
Long life-cycle
Cash
Flo
w
Uncertainty & Risk
Decisions long before
construction
Uncertainty in unit construction costs
Uncertainty in material price
evolution
Uncertainty in timing of M&R activities
CSHub approach characterizes uncertainty
for all three areas
Slide 41
Statistically Characterize Uncertainty
CSHub LCCA methodology is integrated with pavement design process
Present
Future
LCCA Model
Is the difference significant?
Relative risk
Characterize drivers of uncertainty
MEPDG Output
FHWA guidance is limited
Slide 42
IMPLEMENTATION: LCCA – Why does it matter?
• ECONOMICS = LINGUA FRANCA OF IMPLEMENTATION
ECONOMICS100%
26.8 26.9 27.0 27.1 27.2 27.3 27.4 27.5 27.6 27.7 27.80%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
De-sign ADe-sign B
NPV (Millions of $'s)
Cu
mu
lati
ve P
rob
abili
ty
Gambling withCost overrun
Minimizing Risk
Translating price volatility into value proposition for Decision Makers
Slide 43
Analysis:• LCCA & PVI • Pavement maintenance and PVI• Impacts from pavement age
Data needs:• Longer timeframe (7 years doesn’t cover full pavement lifecycle)• Pavement maintenances and activity• More PCC data (i.e. I-295)
Implementation:• Let’s see where this can take us … TOGETHER !
What’s next?
Slide 44
We seek your input!
Thank you.
References:• Louhghalam, A.; Akbarian, M., Ulm, F-J. (2013) Fluegge's Conjecture: Dissipation vs. Deflection Induced
Pavement-Vehicle-Interactions (PVI); J. Engrg. Mech., ASCE.• Louhghalam, A.; Akbarian, M., Ulm, F-J. (2013) Scaling relations of dissipation-induced pavement-vehicle-
interactions; TRB.• http://web.mit.edu/cshub/
Slide 45
• Beyond my pay grade, but…
• CARBON MANAGEMENT is a vehicle of INFRASTUCTURE MANAGEMENT
• Quantitative Sustainability
• Together, let’s make it a reality…
Predicting the future?
Slide 46
: Main distresses of PCC pavements
JPCP Distresses (%slabs)Interstate
D4 D5 D9
Transverse Cracking 11% 10% 0%
Corner Breaks 1% 1% 2%
PCC Patching 8% 2% 2%
Asphalt Patching 13% 12% 1%
Average Pavement Roughness (in/mile) Poor 140-199JRCP IRI 146 128 104
AC IRI 87 73 88
Pavement IRI is a function of pavement maintenance
Slide 47
Comparison: Gen 1 – Gen 2 Model
GPS-1: AC on Granular Base GPS-2: AC on Treated Base
Vehicle speed tons (on 3 axles) m (lane width) (GPS 1, 2 - LTPP Network) sTemperature
Gen
1 I
NP
UT
Gen
2 I
NP
UT
0.0001 0.001 0.01 0.1 1 100
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
Gen-1
Gen-II
DISSIPATED ENERGY [Ltr/100km]
PD
F/1
T=10C/50F (+/- 10C)c=100 km/h (62.5mph)
0.0001 0.001 0.01 0.1 1 100
0.05
0.1
0.15
0.2
0.25
0.3
0.35
0.4
0.45
0.5
Gen-I
Gen-II
DISSIPATED ENERGY [Ltr/100km]
PD
F/1
T=10C/50F (+/- 10C)c=100 km/h (62.5mph)
That is, Gen I model is a lower bound.Gen II is more accurate for local response, but requires (at least) one more parameter.
Slide 48
Viscoelastic Modeling | Master Curve
Load Frequency (Speed)
Temperature 𝑎𝑇=exp (−𝐶1(𝑇 −𝑇 𝑟𝑒𝑓 )𝐶2+(𝑇 −𝑇𝑟𝑒𝑓 ) )
Simplified approach:1 - Accounts for the load frequency effect using a simple Maxwell model in frequency range of interest.
2 - Accounts for temperature effect in the same way as asphalt literature (e.g. William Landel Ferry equation)
From Pouget et al. (2012)
Slide 49
Principle of Viscoelastic Model Fitting (Using Master Curve)
complicated viscoelastic model
Fit for the entire frequency range
Simplified (Maxwell) viscoelastic model
Fit for applicable frequency rangeFind t and E
Simplified Maxwell model along with the WLF law accounts for the temperature dependency.
Maxwell model with temperature dependency
Frequency rangeof interest