Sustainable Concrete Infrastructure Materials and Systems:
Developing an Integrated Life Cycle Design Framework
Part of a
set of 12
Gregory A. Keoleian, Victor C. Li, Stephen E. Kesler, Stuart A. Batterman, Gloria E. Helfand
University of Michigan, Ann Arbor
http://sci.umich.edu
CMS MUSES – 03294
Framework for Integrated Life Cycle Design
Figure 1. Integrated
Life Cycle Design
Infrastructure
Performance
This project is focused on enhancing the
design of infrastructure by integrating
ISMD
materials engineering, civil engineering,
Structural
System
and life cycle analysis.
Maintenance
Properties
Infrastructure
Approach: By pairing a novel Integrated
Loads
Sustainability
Material
Structure
Structures and Materials Design (ISMD)
Shape
Properties
approach with life cycle analysis (LCA)
Construction
tools, an integrated life cycle design
Evaluation Economic
Social
Materials
Material
framework is formed (Figure 1).
Indicators
Constituents
Indicators
Production
Incorporating sustainable design principles
Environmental
Material
Indicators
from nano-scale materials development,
Microstructure
through kilometer-scale infrastructure
performance, this framework uses social,
economic, and environmental indicators to Table 1. Performance Comparison
elevate overall infrastructure sustainability.
Current New ECC
Results: Using LCA feedback, new
“green” Engineered Cementitious
Composites (ECC) contain 74% industrial
waste, reducing burdens, but still exhibiting
exceptional material performance (Figure
2). Applied in an innovative bridge system,
significant improvements in environmental,
social, and economic performance are
seen over a 60 year service life (Table 1).
Indicator
Bridge
System
Bridge
System
Total Primary Energy (GJ)
78,000
46,000
Global Warming Potential
(tonnes CO2 equiv)
5200
3500
Sulfur Oxides (kg SOx)
4700
2600
Total Life Cycle Cost
(million $)
21.0
18.5
Figure 2. Bending of
Green ECC Material
Developed using ISMD
Sustainable Concrete Infrastructure Materials and Systems:
Developing an Integrated Life Cycle Design Framework
Part of a
set of 12
Gregory A. Keoleian, Victor C. Li, Stephen E. Kesler, Stuart A. Batterman, Gloria E. Helfand
University of Michigan, Ann Arbor
http://sci.umich.edu
CMS MUSES – 03294
Life Cycle Assessment of Concrete Infrastructure
Definition: Life Cycle Assessment (LCA) accounts for all material and energy inputs and waste outputs from a
system for all life cycle phases including raw material acquisition, processing, construction, use, and end-of-life.
Bridge Deck Life Cycle
Construction
processes &
traffic delay
Use
normal traffic
conditions
Bridge Repair
Life Cycle Model: The life cycle model includes a traffic flow
End of Life
deck
demolition
Recycling
Construction Related Traffic Congestion
Concrete Bridge Deck Case Study: Bridges and
highway infrastructure are long-lived and capital intensive.
A project that looks preferable in the near term, can prove
to be suboptimal in the long term.
Conventional design
Link slab design
LCA is applied to two concrete bridge deck designs. One, a
conventional expansion joint design and the other, an
engineered cementitious composite (ECC) link slab design.
ECC is a high-performance, fiber-reinforced, ductile
composite.
model, an EPA emissions model (MOBILE6.2) and an equipment
emissions model (NONROAD).
Total Prmary Energy (MJ)
Materials
Extraction &
Processing
9.0E+07
8.0E+07
7.0E+07
6.0E+07
5.0E+07
4.0E+07
3.0E+07
2.0E+07
1.0E+07
0.0E+00
17%
End of Life
13%
85%
80%
Conventional
Distribution
Materials
Construction
Traffic
ECC
Results: The ECC Link Slab Design results in 40% less primary
energy consumption, and 39% less carbon dioxide emissions.
Conclusions: The sustainability of a concrete bridge deck,
evaluated from the perspective of energy consumption,
greenhouse gas emissions, and criteria air pollution can be
improved through incorporation of advanced materials and
designs.
• Accounting for traffic related impacts is a key factor in assessing
transportation infrastructure sustainability.
Sustainable Concrete Infrastructure Materials and Systems:
Developing an Integrated Life Cycle Design Framework
Part of a
set of 12
Gregory A. Keoleian, Victor C. Li, Stephen E. Kesler, Stuart A. Batterman, Gloria E. Helfand
University of Michigan, Ann Arbor
http://sci.umich.edu
CMS MUSES – 03294
Design of Green Cement-based Materials
The sustainability of constructed facilities is
becoming increasingly important, prompting the
development of “greener” environmentallypreferable construction materials.
Approach: Cement-based materials development
focuses both on replacing energy and resource
intensive components using wastes (Table 1) but
also engineering greener materials to improve
Figure 2. Green ECC
Figure 1. Ductility or “bendability”
material properties, such as ductility, strength, and
resistance to large cracks
of green ECC materials
resistance to large cracks or deterioration. These
properties are important for durability and long
Table 1. Industrial Waste Materials Tested
service life. This design is guided by sustainability Fly Ash
Municipal Waste Ash
metrics (social, environmental, and economic) and Cement Kiln Dust
Post-consumer Carpet Fiber
has been termed material “smart greening”.
Waste Foundy Sand
Aluminum Pot Ash
Wastewater Sludge
Banana Fibers
Results: New greener forms of Engineered
Cementitious Composites (ECC) retain properties Table 2. Selected Material Properties and Sustainability Indicators
Ordinary Green
ECC
such as strength, ductility, and fine cracking
Concrete
ECC
Improvement
Material Property
(Figures 1 and 2). These properties are critical to
Strength
(MPa)
28-40
60-70
2X
keeping corrosives out, while reducing energy and
Ductility (%)
0.01
4.0
400 X
resource intensity per liter (Table 2) through waste Maximum Crack Width (mm)
0.3
0.05
6X
material substitution. Increased material energy
Sustainability Indicator
intensity is overcome by using less high
Primary Energy (MJ/L)
2.84
4.7
-1.65 X
Waste Generated (kg/L)
0.32
-1.22
4.8 X
performance ECC material when compared to
CO2 Released (kg/L)
407.2
324.7
1.2 X
concrete over the full infrastructure life cycle.
Sustainable Concrete Infrastructure Materials and Systems:
Developing an Integrated Life Cycle Design Framework
Part of a
set of 12
Gregory A. Keoleian, Victor C. Li, Stephen E. Kesler, Stuart A. Batterman, Gloria E. Helfand
University of Michigan, Ann Arbor
http://sci.umich.edu
CMS MUSES – 03294
Life Cycle Analysis of Concrete Bridge Deck Designs
Definition: Life Cycle Cost Analysis (LCCA) is a full-cost accounting method. Here, applied to highway
infrastructure, it accounts for costs to the funding agency, users, and society throughout the life cycle of the application.
Bridge Deck Case Study: LCCA is applied to two concrete bridge
deck designs. One, a conventional expansion joint design and the
other, an engineered cementitious composite (ECC) link slab design.
ECC is a high-performance, fiber-reinforced, ductile composite.
Life Cycle Costs of Bridge Decks
$100,000,000
$10,000,000
Arrows show when the
conventional design
becomes more costly than
the ECC link slab design
Alternative Bridge Deck Designs
$1,000,000
$100,000
•The ECC link slab design approximately doubles the durability of the
concrete bridge deck by eliminating the expansion joints, meaning
longer deck life and fewer repairs.
• Agency costs account for material, labor and equipment rental and
operation.
• User costs account for time lost to motorists in construction related
traffic delay, increased vehicle operating costs in the construction
zone, and increased risk of vehicle crash in the construction zone.
• Environmental costs account for air pollution damage costs from
increased morbidity and mortality costs due to criteria air pollution, and
the cost of climate change due to greenhouse gases.
• A 4% discount rate is applied to all costs.
$10,000
2000
Note
log
scale
2010 2020
2030
2040 2050
2060
ECC-User
Conv-User
ECC-Agency
Conv-Agency
ECC-Environmental
Conv-Environmental
• Despite that the ECC link slab design is initially more
costly than the conventional design, it resulted in 14%
less total cost and a 30% decrease in agency costs
over the total 60-year life cycle.
• User costs comprise more than 98% of total costs.
• Results are driven by the number and timing of
construction events for repair and rehabilitation.
Sustainable Concrete Infrastructure Materials and Systems:
Developing an Integrated Life Cycle Design Framework
Part of a
set of 12
Gregory A. Keoleian, Victor C. Li, Stephen E. Kesler, Stuart A. Batterman, Gloria E. Helfand
University of Michigan, Ann Arbor
http://sci.umich.edu
CMS MUSES – 03294
Service Life Modeling of Bridge Infrastructure Systems Incorporating New Materials
Results: Predicting the service life and maintenance
schedule of a jointless bridge deck which uses new
ductile Engineered Cementitious Composites (ECC)
(Figure 2), maintenance such as deck repairs and
resurfacing is reduced by as much as 50% over the
90 year bridge service life (Figure 3).
New Deck
Deep Overlay
New Deck
Deep Overlay
Shallow Overlay
6
6
5
Ave = 4.54
4
Ave = 4.69
5
4
Routine Maintenance
3
3
Routine Maintenance
Bridge Model
2
2
Average Value
1
1
0
10
20
30
40
50 60
Age (years)
70
80
Bridge Model
Average Value
NYC Deterioration Model
NYC Deterioration Model
0
New Deck
7
90
0
0
10
20
30
40 50 60
Age (years)
70
80
90
Figure 1. Bridge deterioration models for typical concrete
(left) and jointless ECC bridges (right)
7
Number of Construction Events
Approach: To examine the consequences of new
materials infrastructure service life, a material
deterioration model is combined with a structure
deterioration model (Figure 1). This captures the
dual impact of improved materials along with the
overall effect these materials have on a structure’s
path to failure. It combines numerical predictions of
material performance with real structure
performance records for greater accuracy.
New Deck
7
Structural Deck Rating
Predicting infrastructure service life is critical to
creating accurate life cycle models to assess total
infrastructure costs far into the future. Yet complex
infrastructure systems can fail in countless ways
making development of accurate infrastructure
deterioration models very important, particularly
when implementing new and innovative materials or
construction systems.
Figure 2. Jointless bridge
deck system
6
Concrete
5
4
ECC
3
2
1
0
1
Figure 3. Comparison of bridge
maintenance closings
Sustainable Concrete Infrastructure Materials and Systems:
Developing an Integrated Life Cycle Design Framework
Part of a
set of 12
Gregory A. Keoleian, Victor C. Li, Stephen E. Kesler, Stuart A. Batterman, Gloria E. Helfand
University of Michigan, Ann Arbor
http://sci.umich.edu
CMS MUSES – 03294
Deterioration Modeling of Ductile Cement-based Materials
Prediction of infrastructure service life is critical for
creating accurate life cycle models to assess social,
environmental, and economic sustainability far into the
future. These predictions must be rooted in
deterioration models which estimate how long a
structure will last, and are particularly important for
new materials which have yet to be proven over
decades of use, such as ductile concretes (ECC).
Figure 1. Deteriorated bridge due to concrete chloride
exposure and steel rebar oxidation
Approach: By combining various numerical models
Cl- Cl- that predict migration of corrosives through concrete,
ClCl
Cl
Cl
Cl- Cl Cl- Cl Cl- Cl- Cl Clcrack formation due to expanding rust, and rust
buildup on rebar, the length of time from initial
Corrosive
construction (using regular or ductile concretes) until
ClClMigration
large cracks form due to rusting steel reinforcement
can be calculated. This is based on material
ClClproperties, such as strength or ductility, along with
Single
ECC
structural geometry, and exposure conditions.
concrete
microcracks
crack
Results: In bridge decks that often fail due to rebar
rusting (Figure 1), this modeling shows that new
ductile concretes can last decades longer than typical
concrete by forming microcracks which absorb
Figure 2. Model of steel rebar corrosion and large crack
expanding rust (Figure 2) rather than cracking like
formation in concrete (left) and corrosion and deterioration
concrete and forming bridge deck potholes.
suppression through microcracking in ECC (right).
Sustainable Concrete Infrastructure Materials and Systems:
Developing an Integrated Life Cycle Design Framework
Part of a
set of 12
Gregory A. Keoleian, Victor C. Li, Stephen E. Kesler, Stuart A. Batterman, Gloria E. Helfand
University of Michigan, Ann Arbor
http://sci.umich.edu
CMS MUSES – 03294
Dynamic Life Cycle Modeling of Pavement Overlay Systems
Results: ECC overlay system
reduces greenhouse gas (GHG)
emission by 34%, primary energy
consumption by 14% (Figure 3), and
life cycle cost by 39% (Figure 4).
2.7 m
1"
7"
Existing Reinforced Concrete Pavement
HMA
4"
ECC Overlay
Existing Reinforced Concrete Pavement
2
0
0
6
8"
HMA Overlay
Rubblize Existing Reinforced Concrete Pavement
Figure 1 Overlay Structure
2.5
CO2 80000
CO2
1.5
60000
CO2
1
E
40000
E
0.5
20000
2006 million $
2
Concrete
ECC
2
0
3
6
2
0
4
6
80
60
40
20
0
0
0
2
0
2
6
100
100000
E
2
0
1
6
Overlay
Construction
Minor Repair &
Maintenance
Major Repair &
Maintenance
Figure 2 Timeline
t CO2 equivalent
design (Figure 1), maintenance
schedule (Figure 2), traffic
congestion, and pavement
roughness effects, this LCA-LCC
model evaluates the long-term
sustainability of overlay systems by
dynamically capturing the impacts of
users, construction, and roadway
deterioration.
3.6 m
Concrete Overlay
Energy consump (E), 106 GJ
Approach: Incorporating overlay
3.6 m
ECC Concrete
1.2 m
To improve sustainability in
pavement design, a new bendable
concrete material (ECC) is explored.
An integrated life cycle assessment
and cost (LCA-LCC) model is
developed to evaluate an unbonded
concrete overlay, a hot mix asphalt
(HMA) overlay, and an ECC overlay
over a 40 year life cycle (Table 1).
2006
HMA
Congestion
Usage
Construction
Materials
Distribution
End-of-Life
2016
Concrete
Figure 3 Primary Energy
Consumption & GHG Emission
2026
2036
ECC
2046
HMA
Figure 4 Life Cycle Cost
Table 1 System Definition
Analysis period
Daily Traffic
Lanes
Length
Discount Rate
40 years
70000
4
10 km
4%
Sustainable Concrete Infrastructure Materials and Systems:
Developing an Integrated Life Cycle Design Framework
Part of a
set of 12
Gregory A. Keoleian, Victor C. Li, Stephen E. Kesler, Stuart A. Batterman, Gloria E. Helfand
University of Michigan, Ann Arbor
http://sci.umich.edu
CMS MUSES – 03294
Service Life Modeling of Ductile Concrete Pavement Overlays
Service life prediction is an integral part of life
cycle analysis of infrastructure incorporating new
materials, such as ductile concrete (ECC) in
pavement overlays. These predictions must be
based on dominant deterioration mechanisms
which govern how long the structure will last.
Approach: By combining experimental
investigations that relate the traffic load to service
life and numerical analysis that links the pavement
response with pavement thickness, the service life
can be predicted for given roadway overlay repair.
This is based on material properties, such as
bending strength, along with roadway geometry,
and traffic loads.
Results: For pavement overlay repairs that fail
due to cracks originating from old concrete through
new overlay (Figure 1), this modeling shows that
new ductile concrete pavement overlay repairs can
double the service life of current roadway repairs
with only half of the thickness (Table 1) by forming
microcracks which blunt the pre-existing cracks
rather than forming large potholes (Figure 1).
Table 1. Service life prediction of two overlay scenarios
Bending
Ductility
Thickness Service life
Material
Strength
(%)
(mm)
(years)
(MPa)
Regular
0.01
4.6
200
20
Concrete
Ductile
3.0
12.0
100
40
Concrete
Current overlay after
20 year service life
Current overlay
Old
concrete
Single
large crack
Old concrete
crack
Future ECC overlay after
40 year service life
Microcrack zone
shielding
ECC Overlay
Old
concrete
Old concrete
crack
Figure 1. Current (left) and future ECC (right) overlaid
pavement performance through introduction of ECC
Sustainable Concrete Infrastructure Materials and Systems:
Developing an Integrated Life Cycle Design Framework
Part of a
set of 12
Gregory A. Keoleian, Victor C. Li, Stephen E. Kesler, Stuart A. Batterman, Gloria E. Helfand
University of Michigan, Ann Arbor
http://sci.umich.edu
CMS MUSES – 03294
Network Analysis of Concrete Industry Standards
The concrete industry is heavily reliant on consensus
standards writing organizations to ensure industry-wide
quality and safety. The objective of this study is to
identify institutional barriers and opportunities for
sustainable concrete practice presented by industry
standards.
Figure 1. Network Diagram Representing
ASTM Concrete Specifications
Designation
Approach: Social Networking Theory was used to find
the most heavily referenced industry standards to
identify potential leverage points for sustainable
practice. Standards related to concrete bridge decks
were networked based on their references to each other
(Figure 1). The networks were then evaluated to identify
the most central specifications and provide a framework
for case study analysis.
Results: Based on case study analysis of the three
most heavily referenced standards, centrality (highest
number of references) proves to be an indicator of the
most significant levers and barriers to both sustainable
practice and innovation. The most central standards
prove to be the most difficult to change and generally
the most significant barriers to innovation. Table 1
reflects the most heavily referenced standards among
the American Society of Testing and Materials (ASTM)
specifications evaluated.
Table 1. Most Central ASTM Standards
Description
Portland Cement
Concrete Aggregates
Blended Hydraulic Cements
Chemical Admixtures
Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use as a Mineral Admixture
C09 Terminology
Air Entraining Admixtures
Std. Practice for Proportioning Normal, Heavyweight and Mass Concrete
Specification for Ready Mixed Concrete
C01 Terminology
Designation
C150
C33
C595
C494
C618
C125
C260
C211.1
C94
C219
Sustainable Concrete Infrastructure Materials and Systems:
Developing an Integrated Life Cycle Design Framework
Part of a
set of 12
Gregory A. Keoleian, Victor C. Li, Stephen E. Kesler, Stuart A. Batterman, Gloria E. Helfand
University of Michigan, Ann Arbor
http://sci.umich.edu
CMS MUSES – 03294
Incorporating Pollution Damage Costs into Michigan DOT Life Cycle Cost Analysis (LCCA)
Sustainability requires consideration of long-term
economic, social, and environmental impacts, yet
transportation departments in the US do not integrate
environmental issues (non-user costs) into pavementtype decision making processes (Figure 1).
Approach: A life-cycle assessment model was built to
help evaluate & compare the environmental impact of
asphalt and concrete pavement alternatives for 12 actual
road projects managed by Michigan Department of
Transportation. Impacts from material production and
distribution, equipment use, and work-zone congestion
were included. These were then monetized and
compared with life-cycle agency and user costs currently
taken into account in the MDOT LCCA procedure.
Results: Generally, asphalt pavements have lower lifecycle emissions for some air pollutants (e.g. CO2, NOx,
SOx) but higher for others (e.g. VOC, CH4) than
concrete alternatives (Table 1). Asphalt pavement also
shows higher life-cycle primary energy consumption than
concrete alternatives. However, the pollution damage
costs of both alternatives contributed to less than 9% of
total life-cycle cost, and did not alter the lowest-cost
alternative in the 12 road projects studied.
Life-cycle Cost
Agency
Cost
Pollution
Damage
Cost
User
Cost
e.g. pollution
Figure 1: Life-cycle cost analysis (LCCA)
framework for pavement-type selection
Table 1: Life-cycle environmental impact and damage
costs of pavement alternatives in projects studied
(per dir-mile)
Total Primary
Energy (TJ)
GHG (tonne)
VOC (tonne)
NOx (tonne)
SOx (tonne)
PM (kg)
GHG
VOC
NOx
SOx
PM
Others
Environmental Impacts
Asphalt
Concrete
30-85
>>
10-25
700-3,500
<
1,100-4,100
0.45-1.00
>
0.17-0.70
2.0-6.0
<
2.5-6.2
0.18-0.38
<
0.22-0.44
32-260
~
31-240
Damage Costs
15-30%
22-60%
5-20%
5-10%
-45-65%
-40-55%
10-30%
10-25%
5-20%
5-20%
<1%
<1%
Total $1,000-35,000
$5,000-30,000
Sustainable Concrete Infrastructure Materials and Systems:
Developing an Integrated Life Cycle Design Framework
Part of a
set of 12
Gregory A. Keoleian, Victor C. Li, Stephen E. Kesler, Stuart A. Batterman, Gloria E. Helfand
University of Michigan, Ann Arbor
http://sci.umich.edu
CMS MUSES – 03294
Bendable Concrete Incorporating Ultra High Volumes of Fly Ash
In the development of high performance and high
strength concretes, material sustainability is seldom a
concern and high cement contents are commonly used.
The production of cement is responsible for 5% of
global greenhouse gas emissions. A high performance
bendable concrete (ECC) has been developed taking
into account environmental sustainability.
Approach: Sustainability is improved by incorporating
large amounts of fly ash, a coal power plant waste
product, to replace cement while maintaining/improving
bendable concrete performance The interaction
between material components – fiber, matrix, and fibermatrix interface – is carefully controlled to turn wastes
into beneficial material ingredients.
Results: Bendable concrete using ultra high volumes
of fly ash has been developed with cement content
60% lower than high performance/ strength concretes
(see chart). The resulting material has a tensile
ductility over 300 times that of concrete (see photo)
and tight crack widths about half the thickness of fine
human hair. These properties promote infrastructure
sustainability through simultaneous enhancement of
material greenness and infrastructure durability.
High Performance/Strength
Concrete
Ultra High Fly Ash
Bendable Concrete
Cement
Cement
Coarse Agg
Fly ash
Fine Agg
Sand
Water
Water
SP
SP
Microsilica
Fiber
Sustainable Concrete Infrastructure Materials and Systems:
Developing an Integrated Life Cycle Design Framework
Part of a
set of 12
Gregory A. Keoleian, Victor C. Li, Stephen E. Kesler, Stuart A. Batterman, Gloria E. Helfand
University of Michigan, Ann Arbor
http://sci.umich.edu
CMS MUSES – 03294
Evaluating Michigan DOT Life-Cycle Cost Analysis Practices
Life-Cycle Cost Analysis (LCCA) has become a common tool used by state Departments of Transportation in
pavement-type selection. However, the usefulness of LCCA is dependent on estimating the pavement costs
and performance accurately.
Approach: Application of LCCA in actual Michigan DOT road projects was reviewed. Ten highway sections
were grouped into four case studies. Their estimated and actual accumulated costs and maintenance
schedules were analyzed and compared.
Results: Case studies indicated that Michigan DOT LCCA procedures correctly predict the pavement type
$1.0
$ per km)
(million
Cost
Accumulated
accumulated
cost
($million/km)
($ million/km)
cost(million
accumulated
$ per km)
Cost
Accumulated
with lower initial construction cost, but actual construction costs are usually lower than estimated using LCCA
(Figure 1). This is likely due to non-site specific cost estimation within the Michigan DOT LCCA. Refinements
to pavement construction and maintenance cost estimating procedures would assist the Michigan DOT in
realizing the full potential of LCCA in identifying the lowest cost pavement alternatives.
$0.8
$0.6
$0.4
$0.2
US-131
0
5
10
15
age
Age(years)
(years)
20
25
$1.2
$1.0
Notes:
$0.8
$0.4
* asphalt overlaid on
rubblized concrete
$0.2
#
$0.6
$0.0
I-94
0
5
10
15
age
Age(Years)
(years)
20
25
LCCA estimate (rubb)*
LCCA estimate (asphalt) #
LCCA estimate (conc)
LCCA estimate (asphalt)
actual (rubblized)*
actual (asphalt) #
Actual (conc)
Actual (asphalt)
Figure 1 : Estimated vs. actual costs of pavement of two MDOT managed pavement projects
asphalt overlaid on
repaired concrete