2014 WMA presentation Dec 10 San Diego

WMA& Local Agencies
Brandon Milar, P.E.
Technical Marketing Manager

2 WMA 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

16
Temperature Considerations
•Mix Design
•Mixing, Conditioning, & Compaction
•Ambient
•Production
•Windrow
•Laydown
•Screed
•Breakdown
•Intermediate
•Finish
WMA for Local Agencies; CalAPA SDTC

17
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 Hot Mix
300ºF
Wax and Chemical Additives
Foamed Asphalt
Every 10°degrees increase of temperature doubles exposure to asphalt fumes –BP
00.40.81.21.62 mg/cubic meter TotalOrganicsBenzeneSolublesHot MixWarm 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

30 How 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 1stWMA 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
AsphaltConstruction 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)
WMA
Value
WMA Expectation
HMA
Total Project
Maybe
Production
Yes
-25°F
Reduced Fuel Usage
Yes
Reduced Emissions
Yes
-50°F
Yes
Transport
Maybe
-75°F
Laydown
Improved Compaction
Yes
Reduced Emissions
Yes
Yes

Example #2: WMA @ HMA Production Temps
WMA
Value
WMA Expectation
HMA
Total Project
Yes
Production
Yes
-25°F
Reduced Fuel Usage
No
Reduced Emissions
No
-50°F
No
Transport
Yes
-75°F
Laydown
Improved Compaction
Yes
Reduced Emissions
No
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
brandon.milar@mwv.com
925.852.8668

2014 WMA presentation Dec 10 San Diego

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2014 WMA presentation Dec 10 San Diego