2014 WMA presentation Dec 10 San Diego

WMA&

Local AgenciesBrandon Milar, P.E.

Technical Marketing Manager

2WMA for Local Agencies; CalAPA SDTC

Summary

1. What is Warm Mix Asphalt (WMA)?

2. Why are we shifting to WMA?

3. How do we make WMA?

4. How does an Agency specify WMA?

5. WMA Field Observations


What is WMA


What is Warm Mix?

Asphalt mix that includes a technology which improves the production and placement of conventional asphalt mix at significantly lower temperatures.


Components of Value

Energy Savings

Lower emissions

Reduced worker fatigue

Increased production efficiency

Decreased plant wear

Improved RAP Integration

Longer hauls

Reduced thermal segregation

Cool weather paving

Improved compaction

Improved smoothness

What applies to YOU?


Why are we shifting to WMA


Increased environmental activism has led to:

• Lowering of emission limits

• Reducing exposure to harmful chemicals

• Increasing complaints

• Reducing new HMA plant permits

A “Greener” Planet


Identify and Deploy Innovation that:

• Shortens Project Delivery

• Enhances Roadway Safety

• Protects the Environment

WMA identified as an effective, proven, and market ready technology that the FHWA is prioritizing for accelerated use

FHWA: Every Day Counts


Improvements in mix performance • Increase use of modified

binders

• Increase use of coarse mixes

• Required density

Changes in lane closure requirements• Night Paving

• Take a chance in cool temps

PERFORMANCE!!!


Constructability

Utilizes exiting asphalt paving equipment and methods

Improves workability with high recycle content mixes

WMA helps produce and/or place asphalt mix at lower temperatures:

Reducing RISK!!!


How do we produce WMA


WMA Technologies


Use the same process/equipment as HMA

• Design:

• Utilize WMA technology in design

• Production:

• Dry the Rock!!!

• Placement:

• Treat as NEW mix

• Correlate density measuring devices

• Establish roller pattern and temperature ranges

BMPs


How does an Agency Specify WMA?


Which technology for me?

• Who chooses the technologies?

• Approved?

– Permissive approach

– QPL list

– “National” Qualification

How does WMA fit into existing HMA mix design approval?

Testing Protocol?

Temperature Requirements?

Specifications

1616

Temperature Considerations

• Mix Design

• Mixing, Conditioning, &

Compaction

• Ambient

• Production

• Windrow

• Laydown

• Screed

• Breakdown

• Intermediate

• Finish

WMA for Local Agencies; CalAPA SDTC

1717

Local Agency WMA Use

Portland, OR: WMA required on all Capital Improvement Projects.

Fort Worth, TX & San Antonio, TX: When WMA specified, placement temperature behind the screed must be 235°F or less.

New York City, NY: Use WMA at all City owned hot plants. Use with 40% RAP mixes at low temps (below 32F).

Mexico City, Mexico: Use WMA at all city hot plants to reduce emissions.

New Mexico DOT: All asphalt paving required to be WMA (production below 275F).


18

WMA Field Observations


19

WMA Production Temperature Range

250ºF

200ºF

350ºF

Conventional H

ot

Mix

300ºF

Wax a

nd C

hem

ical A

dditiv

es

Foam

ed A

sphalt

Every 10°degrees increase of temperature

doubles exposure to asphalt fumes – BP

0

0.4

0.8

1.2

1.6

2

mg

/cu

bic

mete

r

Total

Organics

Benzene

Solubles

Hot Mix

Warm Mix


20

62 Deg Difference


21

24 Deg Difference






Cold Weather Paving

New York City,

8 Dec. 08,

40% RAP PG 64-22

Paving

26

Chicago - Increased Recycled Content

Using high amounts of RAP & RAS even in cold temperatures like 25oF.

Reduced equipment wear and tear by lowering the production temperature to 325oF from 365oF (winter production temps).

Better workability with RAP & RAS.

PG 58-22

37% RAP and 5% RAS


27

Binder Hardening


28

Century Asphalt – No Vibrations

Logistical nightmare

• Bridge deck of I-35 in downtown San Antonio, TX

• Milling, then chipseal, then overlay

• All night paving

• Plenty of freeway intersections and ramps

• Type D mix with PG64-22, 16% RAP, 4%RAS

• No vibratory rollers allowed on bridges

• Long truck wait times!

WMA

• 70F drop in production temperature

• Excellent workability even with truck delays

• Rollers ran right behind the screed

• 93.5-94 Densities


WMA Addressing Asphalt Rubber Paving challenges

• Smoke

• Odors

• Compaction

• Temperature

• “Swell”

How to Successfully Marry WMA & GTR, May 16, 2013

30How to Successfully Marry WMA & GTR, May 16, 2013

2600 tons ¾” RHMA-G

0.2’ lift

Ambient = ~60F

Test section in a larger project

Evaluating temperature of mat and compaction

Pounding the Pavement

MIX PROD

(F)

SCREED

(F)

BREAK

(F)

INTER

(F)

FINISH

(F)

CONV 275 250 280 185 155

WMA 250 230 220 170 135


Surpassed 91% min

Same rolling pattern for both conventional and WMA.

Temperature


Lowered Production Temps:

• 275F, 250F, 240F, 230F

Higher Production Rate

• Conv: 295tph@ 275F

• WMA: 375tph @ 250F

250F preferred with this mix



18,000 tons ½” ARHM (Greenbook)

2” lift

Ambient (day) = ~80F

Ambient (night) = ~55F

Long Haul:

1 hour - Newhall

2 ½ hour - Gorman (4000’ el)

Night Paving - Newhall

County’s 1st WMA ARHM Project

Density Achieved

MIX PROD SCREED BREAK INTER FINISH

CONV 325 290 280 250 200

WMA 290 250 240 190 135

MIX Avg (%) BREAK INTER FINISH

CONV 93.2 4V 4V 2V

WMA 94.1 2V 4V 2S


Rolling Pattern

Temperature

36

Smoothness of Thin Lifts and Crack Seal


37

Hall Street, St Louis MO - Side by Side


38

Hall Street, St Louis MO - 5 ½ Years Later



The Value of WMA

Relative

Production

Temperature

Asphalt

Construction

Process

WMA

Value

WMA

Expectation

HMA Total Project Extended Paving Season

Production Improved Aggregate Coating

- 25°F Reduced Fuel Usage

Reduced Emissions

-50°F Increased Recycle Content

Transport Increased Haul Distance

-75°F Laydown Improved Compaction

Reduced Emissions

Improved Worker Comfort


Example #1: WMA @ Reduced Prod Temps (-50F)

Relative

Production

Temperature

Asphalt

Construction

Process

WMA

Value

WMA

Expectation

HMA Total Project Extended Paving Season Maybe

Production Improved Aggregate Coating Yes

- 25°F Reduced Fuel Usage Yes

Reduced Emissions Yes

-50°F Increased Recycle Content Yes

Transport Increased Haul Distance Maybe

-75°F Laydown Improved Compaction Yes

Reduced Emissions Yes

Improved Worker Comfort Yes


Example #2: WMA @ HMA Production Temps

Relative

Production

Temperature

Asphalt

Construction

Process

WMA

Value

WMA

Expectation

HMA Total Project Extended Paving Season Yes

Production Improved Aggregate Coating Yes

- 25°F Reduced Fuel Usage No

Reduced Emissions No

-50°F Increased Recycle Content No

Transport Increased Haul Distance Yes

-75°F Laydown Improved Compaction Yes

Reduced Emissions No

Improved Worker Comfort No


Conclusions

The future of asphalt paving is available TODAY!!!

WMA technologies perform at varying levels and need to be understood by the Contractors

WMA reduces risks in asphalt paving


Thank you!

Brandon Milar, P.E.

Technical Marketing Manager – Evotherm

[email protected]

925.852.8668

mailto:[email protected]

Engineering

2014 WMA presentation Dec 10 San Diego