Sustainability and Resilience of

Concrete Pavements

Milena Rangelov

June 2022

Unless noted otherwise, FHWA is the source for all images

in this presentation.
 

 

 

 

 

 

2

Disclaimer

Except for any statutes or regulations cited, the

contents of this presentation do not have the force and

effect of law and are not meant to bind the public in

any way. This presentation is intended only to provide

information to the public regarding existing

requirements under the law or agency policies.
 

 

 

 

 

 

 

 

3

Acronyms

• EPD Environmental Product Declaration

• GGBFS Ground Granulated Blast Furnace Slag

• LCA Life Cycle Assessment

• LCCA Life Cycle Cost Analysis

• M&R Maintenance and Rehabilitation

• MCTC Mobile Concrete Technology Center

• PCR Product Category Rules

• S-LCA Social Life Cycle Assessment

• SPP Sustainable Pavements Program
 

 

 

 

 

4

Why? Green Public Purchasing Initiatives

Information

collected from

State legislative

websites.

States that legislated green public purchasing

States that have considered green public purchasing legislation in past 2 years
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

5

Executive Order on Federal Sustainability

EO 14057- Catalyzing Clean Energy Industries and Jobs

Through Federal Sustainability [1]

Section 102 (a)(v)

Net-zero emissions from Federal

procurement, including a Buy

Clean policy to promote use of

construction materials with lower

embodied emissions.

Section 303

The Buy Clean Task Force provides

recommendations to the Chair of the Council on

Environmental Quality (CEQ) and the Director

of the Office of Management and Budget (OMB)

on policies and procedures to expand

consideration of embodied emissions and

pollutants of construction materials in Federal

procurement and federally funded projects.

Reference: [1] 86 FR 70935 (Dec. 13, 2021): https://www.govinfo.gov/content/pkg/FR-2021-12-13/pdf/2021-27114.pdf
 

 

 

 

 

 

 

 

 

 

6

Green Public Procurement (GPP)

• Public procurement is the primary economic

activity of government.

−Used by government for pursuit of strategic objectives.

−Influences the remainder of the market and private sector.

−Basic principles: transparency, integrity, economy,

openness, fairness, accountability, competition.

• GPP is the practice of selecting products with

lower environmental impacts than commonly

procured products.
 

 

 

 

 

7

Balance of the Triple Bottom Line

Life-Cycle Assessment

Performance

Sustainability Testing Rating Systems

(e.g., INVEST)

Social LCA

(S-LCA) Life-Cycle Cost Analysis

(LCCA)

Performance

Testing

(LCA)

Image Source: FHWA/APTech
 

 

 

 

8

Life Cycle Assessment

• Technique to quantify environmental impacts

of products and processes

• Covers range of environmental impacts
9

EXAMPLE
 

 

 

 

 

 

10

A Research Study on Paving Concrete

• Collaborative study of SPP and MCTC

• Study objectives:

− Evaluate the state of practice for paving concrete

− Identify the opportunities for improvement

− Identify strategies for pavement agencies to achieve GHG

savings for concrete pavements

Source: FHWA
 

11

MCTC Concrete Paving Projects (2011-2019)

Source: FHWA
12

Aggregate

Cement

Admixtures

Concrete

mixing

Aggregate

production

Cement

production

Admixture

production

Concrete

mixture

Water

T

T

T

T

T

T

SCM SCM

processing

T T

Analysis

Scope:

Cradle-to-gate

Legend:

T Transportation

Materials Wastes

Energy Emissions

System boundary

A1 A2 A3

Material production Transport Mixing

Source: FHWA
 

 

 

 

 

 

 

 

 

13

Mixture Statistics

Cementitious material content [lbs/yd3] Paste content [%]

Count [-]

Count [-]

Recommended

limit for paving

mixtures from

AASHTO PP-84

Typical minimum

cementitious

content for

slipform paving

Source: FHWA

• Most mixtures use cementitious content in the

higher range of specifications.

• 17 mixtures have paste content above 25 percent

(AASHTO PP84).

AASHTO PP84 is a voluntary industry specification. Its use is not required by Federal law.
 

 

 

 

 

 

 

 

 

 

14

GWP vs. Mixture Design

500 500

Binary- FA C

Binary- FA F

Binary- GGBFS

Ternary

Plain

Binary- NP

450 450

Binary- FA C

Binary- FA F

Binary- GGBFS

Ternary

Plain

Binary- NP

GWP [kg of CO2 eq.]

GWP [kg of CO2 eq.]

400 400

350 350

300 300

250 250

200

300 350 400 450 500 550 600 650

200

20% 21% 22% 23% 24% 25% 26% 27% 28% 29%

Cement content [lb./yd3] Paste content [%]

Source: FHWA

• Strong positive linear correlation between cement

content and GWP.

• Increase in paste content leads to GWP increase.
 

 

 

 

15

Process Contributions

100% 500

90% 450

80% 400

GWP percentage [%]

70%

60%

50%

40%

30%

20%

10%

0%

350

300

250

200

150

100

50

0

Total GWP [kg of CO2 eq.]

AL

AZ

AR

CA-1CA-2CA-3CA-4

CO

DE

FL

HIID

IL

IA

KS

MI

NV

NM

NC-1NC-2

ND

OH

PA

TE

VA

WAWV

WI

Cement Aggregate Transportation GGBFS Mixing Total GWP Source: FHWA

• With contribution of 73-93%, cement is the most significant

contributor to GWP.

• Other processes with noteworthy contribution include transport

and slag processing.
 

 

 

 

 

 

 

 

 

 

16

Potential Savings in Analyzed Projects

16% 90,000

Binary- FA C

Binary- FA F

Binary- GGBFS

Binary- NP

Ternary

Plain

Total GWP reduction [kg of CO2 eq.]

Binary- FA C

80,000 Binary- FA F

70,000 Binary- GGBFS

14%

12%

10%

8%

6%

GWP

4%

reduction [%]

B

Ternary

inary- NP 60,000

50,000 Plain

40,000

30,000

20,000

2% 10,000

0%

0% 1% 2% 3%

Paste reduction [%]

4% 5%

0

0% 1% 2% 3%

Paste reduction [%]

4% 5%

Source: FHWA

• % of GWP savings are proportional to % in paste reduction.

• Total savings per 1 lane mile can amount to removing up to

27 commuters from the road for a year.
 

 

 

 

 

 

 

 

 

17

Potential Savings inAnalyzed Projects

% savings in embodied carbon when paste content is

reduced to 25%

AL

AZ

CA-1

CA-2

CA-3

CA-4

DE

HI

ID

IL

NV

NM

NC-1

NC-2

PA

VA

WA

WV

Project code

Reducing paste content to

recommended 25% is:

- Providing improved

performance

- Reducing embodied

carbon by up to 16%

- Captured in EPDs

- Readily implementable

- Cost-effective

0% 2% 4% 6% 8% 10% 12% 14% 16%

% savings
 

 

 

 

18

Concrete Pavement Decarbonization

Strategies from the Literature

Strategy Readiness

level

Carbonation

management

level

Lifecycle

phase

Economic

indicators Stakeholders

CO2 curing Medium Offset Material

production Higher cost Concrete

producers

Material

efficient design High Reduce Materialproduction Lower cost Concrete

Material

substitution High Replace Materialproduction Lower cost producersand State

Service-life

extension High Offset Use Depends DOTs

Increased EOL

carbonation High Offset EOL Higher cost

State DOTs

and

contractors

Source: FHWA
 

19

CLOSER LOOK AT EPDs
 

 

 

 

 

 

 

20

What Are EPDs?

• Communicate

environmental impacts of

material or product.

• Express the results of an

LCA.

• Developed with stakeholder

input.

• Follow industry standards

described in the PCR.

• EPDs are not required by

Federal law or regulation.

Source: FHWA.
 

21

Pavement Product System
 

 

 

 

22

LCA Benchmarking Tool

• Created with stakeholder input

• Use the identified background datasets

• Incorporate material EPDs

Available at: https://www.fhwa.dot.gov/pavement/lcatool/
 

 

 

 

 

 

23

Would you like to get involved?

• Register for SPTWG Meeting – SPTWG Website

• Join the newsletter – Join to become a SPP Friend

• Request LCAPave Demo - email

LaToya.Johnson@dot.gov

• Learn about pooled fund – Pooled Fund Solicitation

• Learn about Climate Challenge- Climate Challenge

• Learn about our resources –next slide
 

 

 

 

 

24

Resources

Education Research Deployment

Pavement LCA

Framework

Webinars

Tech briefs, studies

LCA fit in transportation

decision-making

EPDs in Green Public

Procurement

LCA of recycled plastics in

pavements

LCAPave Tools

Pilot projects with State

DOTs

Mobile Pavement

Technologies Centers

Technical articles LCA of ground tire rubber in Informing pre-engineering

pavements with ICE Tool
25

Milena Rangelov

Research

Deployment

Education

Milena.Rangelov.ctr@dot.gov

Migdalia Carrion

Migdalia.Carrion@dot.gov

LaToya Johnson

LaToya.Johnson@dot.gov

 

 

http://www.fhwa.dot.gov/pavement/sustainability