6th ISAP APE; Haslett, Dave, Mo; October 2019
Climate-change Informed Life Cycle Assessment for Pavement
Rehabilitation and Maintenance Decision Process
Eshan V. DaveUniversity of New Hampshire
6th ISAP APE; Haslett, Dave, Mo; October 2019 2
Katie HaslettPh.D. Student
Co-AuthorsWeiwei Mo
Assistant Professor
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Outline Introduction• Motivation for study Background• Life Cycle Assessment (LCA)• Pavement Management Methodology• Future climate data• Realistic traffic conditions• Pavement performance Selected LCA Results Conclusion and Summary
6th ISAP APE; Haslett, Dave, Mo; October 2019
Motivation…U.S. Conditions U.S. highway system is one of the world’s largest consisting of 7 million miles (11.3 million km) of road length According to USDOT, by the year 2045:• U.S. population will spend over 42 hours stuck in traffic
each year per person• Annual cost of congestion in delays and lost fuel is
estimated to be $160 billion• Annual cost of truck congestion alone is $28 billion
Need to design and maintain roadways efficiently and effectively over service life
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6th ISAP APE; Haslett, Dave, Mo; October 2019
Traditional pavement management is based on performance and economic factors… do not incorporate environmental impactsPavement analysis and performance evaluation is often conducted using historical climate data• However, flexible pavements are sensitive to
climatic stressors and performance is influenced by changing climate
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Challenges (1/2)
6th ISAP APE; Haslett, Dave, Mo; October 2019
Including both user and agency impacts during the operation phase of an LCA is important for resiliency ofpavement management system
• Unlike so called “Cradle to Gate” LCA for product “carbon foot-printing”
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Challenges (2/2)
6th ISAP APE; Haslett, Dave, Mo; October 2019
To develop LCA framework that incorporates:
Future climate projections Realistic traffic conditions Ability for consequential analyses of various
Maintenance and rehabilitation (M&R) strategies
Pavement and Asphalt Materials:
Performance prediction with future climate
Quantify changes in fuel consumption and resulting emissions due to pavement distresses and roughness (IRI)
LCA inventory7
Objectives
6th ISAP APE; Haslett, Dave, Mo; October 2019
LCA is a technique used to assess cost and environmental impacts associated with various stages of a product’s design life.
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Background: LCA
For LCA to be impactful, all phases of system should be included!LCA OutcomesGlobal Warming Potential (GWP)Cumulative Energy Demand (CED)Life Cycle Costs (LCC)
6th ISAP APE; Haslett, Dave, Mo; October 2019
Pavement Management Optimization using pavement performance for M&R decisions
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Background: Pavement Management
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Outline Introduction• Motivation for study Background• Life Cycle Assessment (LCA) Methodology• Future climate data• Realistic traffic conditions• Pavement performance Selected LCA Results Conclusion and Summary Contributions
6th ISAP APE; Haslett, Dave, Mo; October 2019 11
1. Select Project Domain and Identify Baseline Conditions
2. Inventory
3. Realistic Traffic Data
4. Pavement Performance
5. LCA Impact Assessment
Length: 26 km / 16 miles Location: I-495, MA Baseline: No maintenance treatment (also for comparison,
constant traffic speed)
Material properties, traffic volumes, climatic information, pavement structures
Unit impacts of material, construction, operation etc.
Data mining from Google maps for trip delay times Varying acceleration and deceleration scenarios inferred
from traffic delay (green, orange, red, dark red) Utilize EPA MOVES software to calculate emissions
Simulate pavement cross sections with varying materials as well as maintenance & rehabilitation options
Consider future climate projections Pavement distresses, International Roughness Index (IRI)
Quantify GWP, CED and LCC for each scenario Optimize
General Methodology
6th ISAP APE; Haslett, Dave, Mo; October 2019
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Existing Subgrade
2" Surface Course
5" AC Binder Course
8" AC Base Course
24" Granular Base
5 cm
12.5 cm
20 cm
60 cm
Pavement Cross-Section and Mixtures
Asphalt Mixture CharacteristicsCross
Section # Mix Name PG Grade AC (%) VMA VFA
Surf
ace
Cou
rses
1 ARGG-1 58-28 7.8 19.4 77.82 ARGG-2 58/28 7.6 18 803 T-1 64-28 5.4 15.57 77.644 THS-1 76-28 5.4 15.57 77.645 SHM-1 70-34 (PMA) 5.5 14.9 80.5
Bin
der
Cou
rse
- B-1 64-28 4.8 15 68.6
Bas
e C
ours
e
- BB-1 64-28 4.8 14.8 69
6th ISAP APE; Haslett, Dave, Mo; October 2019
Coupled Model IntercomparisonProject Phase 5 (CMIP5) Variables: Precipitation, Max. and Min. temperature Coverage: 1950-2099 Temporal Resolution: Daily Spatial Resolution: 12km by 12km grid Climate Scenarios:• Current Emissions• RCP4.5: Radiative forcing stabilizes
at ~4.5 W/m2 after 2100• RCP8.5: Radiative forcing reaches
~8.5 W/m2 at 2100
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Downscaling is the general name for a procedure to take information known at large scales to make predictions at local scales.
Future Climate Data
6th ISAP APE; Haslett, Dave, Mo; October 2019
-20.00-10.00
0.0010.0020.0030.0040.0050.00
0 360 720 1080 1440 1800 2160 2520 2880 3240 3600Tem
per
atu
re (
deg
. C
)
Days
Maximum Daily Temperature (1950-1960)
-20.00-10.00
0.0010.0020.0030.0040.0050.00
0 360 720 1080 1440 1800 2160 2520 2880 3240 3600Tem
per
atu
re (
deg
. C
)
Days
Maximum Daily Temperature (2020-2030)
CMIP5: RCP 8.5
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1. Select Project Domain and Identify Baseline Conditions
2. Inventory
3. Realistic Traffic Data
4. Pavement Performance
5. LCA Impact Assessment
Length: 26 km / 16 miles Location: I-495, MA Baseline: No maintenance treatment (also for comparison,
constant traffic speed)
Material properties, traffic volumes, climatic information, pavement structures
Unit impacts of material, construction, operation etc.
Data mining from Google maps for trip delay times Varying acceleration and deceleration scenarios inferred
from traffic delay (green, orange, red, dark red) Utilize EPA MOVES software to calculate emissions
Simulate pavement cross sections with varying materials as well as maintenance & rehabilitation options
Consider future climate projections Pavement distresses, International Roughness Index (IRI)
Quantify GWP, CED and LCC for each scenario Optimize
General Methodology
6th ISAP APE; Haslett, Dave, Mo; October 2019
RTD: Accounts for user costs/emissions with respect to realistic driving conditions Google Maps Daily hourly patterns• Each hour for each day of week (9-10 am on
Monday)
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Realistic Traffic Data (1/3)
6th ISAP APE; Haslett, Dave, Mo; October 2019
Simulate realistic driving conditions• Acceleration, deceleration, stoppage in various
phases (green, orange, red, maroon)• SHRP2 Naturalistic
Driving StudyHourly VehicleVolumes• MassDOT Traffic
Data ManagementSystem
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Realistic Traffic Data (2/3)
6th ISAP APE; Haslett, Dave, Mo; October 2019
EPA Motor Vehicle Emissions Simulator (MOVES)• Vehicle specific power-
based simulations of fuel usage and emissions
• GWP and CED as a function of road roughness (IRI) and realistic traffic (accelerations, decelerations, stoppage etc.)
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Realistic Traffic Data (3/3)
y = 0.003x + 36.206
36.336.436.536.636.736.836.9
0 50 100 150 200 250Glo
bal W
arm
ing
Pote
ntia
l (G
g C
O2
Eq.)
IRI (in/mi)
Monthly GWP
6th ISAP APE; Haslett, Dave, Mo; October 2019 19
1. Select Project Domain and Identify Baseline Conditions
2. Inventory
3. Realistic Traffic Data
4. Pavement Performance
5. LCA Impact Assessment
Length: 26 km / 16 miles Location: I-495, MA Baseline: No maintenance treatment (also for comparison,
constant traffic speed)
Material properties, traffic volumes, climatic information, pavement structures
Unit impacts of material, construction, operation etc.
Data mining from Google maps for trip delay times Varying acceleration and deceleration scenarios inferred
from traffic delay (green, orange, red, dark red) Utilize EPA MOVES software to calculate emissions
Simulate pavement cross sections with varying materials as well as maintenance & rehabilitation options
Consider future climate projections Pavement distresses, International Roughness Index (IRI)
Quantify GWP, CED and LCC for each scenario Optimize
General Methodology
6th ISAP APE; Haslett, Dave, Mo; October 2019 20
Maintenance & rehabilitation alternatives
• Do Nothing Reconstruct (DNR)• Crack Sealant (CS)• Microsurfacing (MS 2.2 m/km or 140 in/mi)• Microsurfacing (MS 2.5 m/km or 160 in/mi)• Cold-In-Place Recycling (CIR)• Mill & Overlay (MO)
6th ISAP APE; Haslett, Dave, Mo; October 2019
Performance predicted for 6 M&R scenarios:• AASHTOWare Pavement ME
• Do Nothing Reconstruct (DNR) Cold-In-Place Recycling (CIR) Mill & Overlay (MO)
• Pavement Sections and Data:• Crack Sealant (CS)• Microsurfacing (MS 2.2 m/km or 140 in/mi)• Microsurfacing (MS 2.5 m/km or 160 in/mi)
Thresholds:• Initial IRI = 1 m/km (63 in/mi)• Terminal IRI = 2.7 m/km (172 in/mi)• Minimum 3 full M&R cycles
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Literature Sources: Cole et al., 2016 Gary Fitts, 2003 Nair et al., 2015 Lane et al., 2005 Mousa et al., 2018 Stephen Damp, 2008 …others
Performance Prediction
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Pavement Performance
Maintenance Alternatives
Maintenance Alternatives
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Pavement Performance
Maintenance Alternatives
Maintenance Alternatives
6th ISAP APE; Haslett, Dave, Mo; October 2019 24
Outline Introduction• Motivation for study Background• Life Cycle Assessment (LCA) Methodology• Future climate data• Realistic traffic conditions• Pavement performance Selected LCA Results Conclusion and Summary Contributions
6th ISAP APE; Haslett, Dave, Mo; October 2019
6.4% increase in GWP and CED with the inclusion of RTD (monthly average shown)
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Results: Effects of RTD
6th ISAP APE; Haslett, Dave, Mo; October 2019
0
5
10
15
20
25
30
35
40
CS DNR CIR MO MS140
MS160
MS140
CS MO DNR CIR MS160
Cross-Section-1 Cross-Section 3
Year
ly C
ost (
Milli
ons
of D
olla
rs)
Yearly Cost ComparisonUser Cost Const./Maint. Cost
Results: Life Cycle Costs with Future Climate
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17.7% difference in operation cost (users)
41.1% difference in construction/maint. cost (agency)
6th ISAP APE; Haslett, Dave, Mo; October 2019 27
Most Economical
Least Economical
Net Present Value (Historical Climate Data)Cross
SectionMaintenance Alternative (in millions of $)
DNR CS MS (IRI =140) MS (IRI =160) CIR MO1 $232 $219 $187 $191 $158 $1572 $231 $219 $187 $156 $158 $1573 $232 $224 $187 $191 $158 $1574 $267 $252 $219 $199 $1595 $299 $277 $253 $215 $160
Net Present Value (Future Climate Data)Cross
SectionMaintenance Alternative (in millions of $)
DNR CS MS (IRI =140) MS (IRI =160) CIR MO1 $264 $252 $212 $212 $158 $1573 $269 $256 $218 $212 $158 $157
Average percent difference from MO alternative (most economical):• CIR = 0.678 %• MS 160 = 13.1 %• MS 140 = 17.5 %• CS = 33.7 %• DNR = 38.3 %
• CIR = 0.683 %• MS 160 = 29.6 %• MS 140 = 31.0 %• CS = 47.0 %• DNR = 51.7 %
With Future Climate Data
Results: Life-Cycle Costs(Agency)
6th ISAP APE; Haslett, Dave, Mo; October 2019
The average increase in NPV using future climate to historical climate with respect to the most economical M&R strategy (Mill and Overlay):• CIR = 0.79%• MS 160 = 77.5%• MS 140 = 55.6 %• CS = 33.0%• DNR = 29.7 % For this highway MO or CIR may be more economically
resilient M&R strategy in terms of costs in future climate conditions.
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Results: M&R Cost Comparisons
6th ISAP APE; Haslett, Dave, Mo; October 2019
0
100
200
300
400
500
600
CIR CS DNR MO MS140
MS160
CIR CS DNR MO MS140
MS160
Cross-Section 1 Cross-Section 3
Glo
bal W
arm
ing
Pote
ntia
l (G
g of
CO
2eq
/yr)
Global Warming Potential Comparison
Const./Maint. Users
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19.6% difference in operation GWP (users)
70.1% difference in construction/maintenance GWP (agency)
Results: Lifetime Impacts
6th ISAP APE; Haslett, Dave, Mo; October 2019
Use-phase should not be ignored! Substantially larger GWP contributions Cumulative user costs are substantially larger than
agency costs Inclusion of RTD is critical for LCA 6.4% increase GWP and CEDUse of historic climate data in pavement management could result in lack of resiliency Up to 8% user and 38% agency GWP and CED
increase
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Summary and Conclusions (1/2)
6th ISAP APE; Haslett, Dave, Mo; October 2019
In general, the ranking of M&R alternatives remains constant but the margin of difference in costs increased among different M&R scenariosOptimization of pavement structure, M&R type and timing has different impacts for agencies and users
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Summary and Conclusions (2/2)
6th ISAP APE; Haslett, Dave, Mo; October 2019
Explore more M&R strategies and a combination of strategies over the service life of the roadway
Investigate the effect of future climate on the effectiveness of certain M&R strategies
Perform LCA using a probabilistic approach, esp. for future climate projections
Improve operational impact component of LCA
Expand framework for network level pavement management decision support
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Future Extensions
6th ISAP APE; Haslett, Dave, Mo; October 2019
1. Qiao, Y., Dave, D., Parry, T., Valle, O., Mi, L., Ni, G., Yuan, Z., and Zhu, Y., 2019. Life Cycle Costs Analysis of Reclaimed Asphalt Pavement (RAP) Under Future Climate. Sustainability 2019, 11(19), 5414; https://doi.org/10.3390/su11195414.
2. Haslett, K.E., E.V. Dave, and W. Mo, “Realistic Traffic Condition Informed Life Cycle Assessment: Interstate 495 Maintenance and Rehabilitation Case Study,” Sustainability, 11(12), p. 3245, 2019. https://doi.org/10.3390/su11123245
3. Knott, J.F., J.E. Sias, E.V. Dave, and J.M. Jacobs, “Seasonal and Long-Term Changes to Pavement Life Caused by Rising Temperatures from Climate Change, Transportation Research Record, 2019. DOI: https://doi.org/10.1177/0361198119844249
4. Knott, J.F., J.M. Jacobs, J.E. Sias, P. Kirshen, and E.V. Dave, “A Framework for Introducing Climate-Change Adaptation for Pavement Management,” Sustainability, 11(16), p. 4382, 2019. https://doi.org/10.3390/su11164382
5. Y. Qiao, E.V. Dave, and T. Parry, “Life-Cycle Cost Analysis of Reclaimed Asphalt Pavement (RAP) under Future Climate: A New Hampshire Interstate-95 Case Study,” Proceedings of the International Seminar on Resilient Roads and Climate Change Adaptation, Beijing, China, 2018
6. O. Valle, Y. Qiao, E. Dave, and W. Mo, “Life Cycle Assessment of Pavements Under a Changing Climate,” Pavement Life-Cycle Assessment, ISBN: 978-1-138-06605-2, CRC Press, pp. 241-250, 2017. http://dx.doi.org/10.1201/9781315159324-25
7. C. DeCarlo, W. Mo, E.V. Dave, and J. Locore, “Sustainable Pavement Rehabilitation Strategy using Consequential Life Cycle Assessment: An Example of Interstate 95,” Proceedings of the Tenth International Conference on the Bearing Capacity of Roads, Railways and Airfields (BCRRA 2017), Taylor and Francis Group, London, pp. 2193-2200, 2017
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Publications
6th ISAP APE; Haslett, Dave, Mo; October 2019
Acknowledgements
• Minnesota Department of Transportation• UNH Center for Infrastructure Resilience
to Climate
• Contact: [email protected]
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Thank you for your attention!
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