Utilizing Chemical WMA
to Achieve Sustainability
Goals and Reduce
Emissions
Ashley R. Batson
Manager of Government Relations, Road
Construction
Ingevity Corporation
1

Introduction
Brief History of WMA
Current Use of WMA
Utilizing Chemical WMA to Reduce Emissions
Utilizing Chemical WMA to Reach Net Zero Goals
Economic Benefits to WMA
How Do We Implement True WMA?
Agenda

Introduction
1

California’s Climate Goals
Image Source: CARB Website
• Reduce GHG Emissions below 40% of 1990 Levels
by 2030
• Reduce GHG Emissions below 80% of 1990 Levels
by 2050
• 2022 Draft Scoping Plan seeks to achieve Carbon
Neutrality by 2045
What can the asphalt pavement industry do to
help reduce emissions?

Brief History of WMA
2

Data taken from NAPA’s “Asphalt Pavement Industry Survey on Recycled Materials and Warm-Mix Asphalt Usage: 2019”
NAPA Survey on WMA Usage
0
20
40
60
80
100
2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
WMA
Technology
Usage
(%)
Percentage of WMA Placed by Technology Type
Production Plant Foaming Chemical Additive Organic Additive Additive Foaming
NAPA Released Survey
in March 2022

NAPA Survey on WMA Usage
7
WMA technology is
in ≈50% of our
asphalt tonnage.
BUT… is it really
WMA if we haven’t
reduced temps?

Current Use of WMA
3
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❑ Cheap Insurance
❑ Improved compaction
❑ Density bonus
❑ Reduce rollers
❑ Cold Weather Paving
❑ Start earlier – pave longer
❑ Long Haul – Better Silo Storage
❑ Reduced Absorption – Lower AC Content
❑ Liquid Anti-Strip and Lime replacement
❑ Increased recycle usage – improved workability
❑ Decrease mix temperature
❑ Reduced thermal segregation
❑ Longer binder life
❑ Reduced fuel consumption
❑ Reduced emissions
❑ BMD
Current Use of WMA

Utilizing WMA to
Reduce Emissions
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Emerging Industry Issues
11
• Environmental Justice Concerns (Plant Odors and Visible
Emissions)
• Buy Clean/ GHG Reduction Initiatives/Requirements
• Improving Long-term Performance
• BMD Migration
• HMA to WMA Conversions

OSHA
Hazard
Mitigation
OSHA Hazard Mitigation "Hierarchy of Control"

Higher Production Temps = Increased Emissions
13

Fugitive Emissions at the Plant
HMA @ 315°F
WMA @ 260°F

Mitigation vs Prevention
HMA @ 315°F WMA @ 260°F

Emissions Reductions Benefits with True WMA
16
Run #4 325F
AVG Mix Temp
Run #1 AVG
305F Mix Temp
APT Device
Run #2 280F
AVG Mix Temp
Run #3 260F
AVG Mix Temp

Fugitive Emissions – Visible Particulate Matter
85.3
71.0
7.5
11.9
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
Top of Silo Load Out
Concentration,
mg/m³
Average Particulate Matter (PM10) Emitted over 1-Hour
Run
315°F 260°F
0
20000
40000
60000
80000
100000
120000
0 10 20 30 40 50 60
Concentration,
µg/m³
Time, minutes
Comparison of HMA and WMA Particulate Matter (PM10)
Emissions on Top of Silo
315°F 260°F

Fugitive Emissions: Load Out
12.1
7.8
3.8
80.5
41.9
11.1
0.0
10.0
20.0
30.0
40.0
50.0
60.0
70.0
80.0
90.0
340°F 295°F 255°F
Total
PPM
Day 1: Load Out
PM 1
PM 2.5
1.7
0.9 1.0
11.5
4.7
2.8
0
2
4
6
8
10
12
14
340°F 295°F 255°F
PPM
Day 1: PPM/Load Out
PM 1
PM 2.5

Fugitive Emissions: Paver
39.4
22.5
13.6
88.8
34.4
19.8
0
10
20
30
40
50
60
70
80
90
100
340°F 295°F 255°F
Total
PPM
[1hr]
Fugitive Emissions: Paver
PM 1
PM 2.5
0.66
0.38
0.23
1.48
0.57
0.33
0
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
340°F 295°F 255°F
PPM/Min
Fugitive Emissions: Paver
PM 1
PM 2.5

WMA Environmental Benefits –Fugitive
Emissions
20
-66%
-48%
-61%
-14%
-86%
-78%
-47%
-100%
-80%
-60%
-40%
-20%
0%
Chute Load Out Paver Screed
Concentration
(PPM/Min)
Fugitive Emissions (PM 2.5) Reduction by
Temperature
295°F 250°F
-78% -81%
-73%
-41%
-65%
-61%
-100%
-80%
-60%
-40%
-20%
0%
Auger Box Hopper Screed Silo #2 Silo #3 Top of Silo
Concentration,
PPM
Fugitive Emissions (PM2.5) Reduction by
Temperature
260°F
Reduction from 340°F Reduction from 320°F

WMA Environmental Benefits – Stack Emissions
21
-17%
-70%
-9%
-33%
-12%
-79%
-28%
-35%
-100%
-80%
-60%
-40%
-20%
0%
PM CO NOx VOC
Concentration
(lb/hr)
Stack Emissions Reduction by Temperature
295°F 250°F
Ohio - 2021 Utah - 2022
Reduction from 340°F Reduction from 325°F
-33%
-45%
-28%
-48%
12% 10%
-5%
1%
-60%
-40%
-20%
0%
20%
PM CO NOX VOC
Concentration,
lb/hr
Stack Emissions Reduction by Temperature
260°F 325°F with lime

Utilizing WMA to
reach Net Zero
Goals
5
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23
Our Industry Needs Leaders…

Ingevity Environmental Product Declarations

What does the future look like?
250º
200º 350º
300º
HMA
True Warm Mix Hot WMA
275º
225º 325º

Our Path to Net Zero
26
0%
20%
40%
60%
80%
HMA Foam Evotherm 3G Evotherm DAT Evotherm ET CCPR CIR
Percent
Reduction
in
CO
2
e
CO2e Reduction (%) for WMA Technology
15-30%
40-50%
250 - 280°F
<100°F
30-40%
230
-260°F
190
-220°F
40-60%
<100°F
75-90%
<10%
>285°F

• BMD is coming… WMA will help!
• True WMA improves Ideal CT
• Binder Tests (ΔTc) improves significantly at True WMA production and conditioning
temperatures (< 275° F)
• Hamburgs are typically as good, or better, with chemical WMA
• True WMA is more cost-effective & more sustainable than REDUCING RAP,
INCREASING AC or ADDING REJUV to meet BMD requirement—all of which improve
your mix EPD
• Pavement life extension of 20-30% when temperatures are reduced by at least
50F—all of this leads to a more sustainable asphalt pavement
WMA within BMD Framework

Economic
Benefits to WMA
6

How do we
implement True
WMA?
7
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Federal Funding for Sustainable Pavements
• IIJA’s Carbon Reduction Program
– $6.4B over 5 years
• $555.2M for California over 5 years
– FHWA Guidance made pavements eligible:
• “Sustainable pavements technologies that reduce embodied carbon during the
manufacture and/or construction of highway projects could be eligible for CRP if a
lifecycle assessment (LCA) demonstrates substantial reductions in CO2 compared to
the implementing Agency’s typical pavement-related practices. The LCA Pave Tool
can be used to assess the CO2 impacts of pavement material and design decisions.”
• Numerous other federal programs incentivize sustainable construction practices
• CalTrans awarded FHWA Climate Challenge funds for a project that includes
quantification of emissions for HMA vs WMA to be completed in 2 years.

Agency Options
DOT pays for WMA as a
separate line item.
Similar model to asphalt
binder in SC or LAS in TN
Line Item Pay
WMA Temperature
Specifications
$1/ton Bonus < 290°
Production Temperature
$2/ton Bonus < 270°
Production Temperature
Road Owner Specifies Max
Production Temperature
Incentive
Specifications

• California goals—a, b, c, d,
• Here is a proven technology which can make an impact
today…how do we get there?
• CalTrans Climate Challenge Project with Goal to obtain
funding for Low Temperature Asphalt
• Industry Partnerships to Compare HMA vs WMA and collect
emissions and fuel data
• Reduced Temperature Incentive Spec Development
• Additional WMA Data Collection - Fugitive Emissions
Next Steps

True WMA Is Good For Our…
• People
• Planet
• Performance
• Profitability

Questions
Ashley Batson
Manager of Government Relations, Road
Construction
(803)-730-0571
Ashley.batson@ingevity.com