2014 WMA presentation Dec 10 San Diego
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Transcript of 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
3WMA for Local Agencies; CalAPA SDTC
What is WMA
4WMA for Local Agencies; CalAPA SDTC
What is Warm Mix?
Asphalt mix that includes a technology which improves the production and placement of conventional asphalt mix at significantly lower temperatures.
5WMA for Local Agencies; CalAPA SDTC
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?
6WMA for Local Agencies; CalAPA SDTC
Why are we shifting to WMA
7WMA for Local Agencies; CalAPA SDTC
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
8WMA for Local Agencies; CalAPA SDTC
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
9WMA for Local Agencies; CalAPA SDTC
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!!!
10WMA for Local Agencies; CalAPA SDTC
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!!!
11WMA for Local Agencies; CalAPA SDTC
How do we produce WMA
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WMA Technologies
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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
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How does an Agency Specify WMA?
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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).
WMA for Local Agencies; CalAPA SDTC
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WMA Field Observations
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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
WMA for Local Agencies; CalAPA SDTC
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62 Deg Difference
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24 Deg Difference
WMA for Local Agencies; CalAPA SDTC
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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
WMA for Local Agencies; CalAPA SDTC
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Binder Hardening
WMA for Local Agencies; CalAPA SDTC
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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 for Local Agencies; CalAPA SDTC
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
How to Successfully Marry WMA & GTR, May 16, 2013
Surpassed 91% min
Same rolling pattern for both conventional and WMA.
Temperature
32How to Successfully Marry WMA & GTR, May 16, 2013
Lowered Production Temps:
• 275F, 250F, 240F, 230F
Higher Production Rate
• Conv: 295tph@ 275F
• WMA: 375tph @ 250F
250F preferred with this mix
33How to Successfully Marry WMA & GTR, May 16, 2013
34How to Successfully Marry WMA & GTR, May 16, 2013
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
How to Successfully Marry WMA & GTR, May 16, 2013
Rolling Pattern
Temperature
36
Smoothness of Thin Lifts and Crack Seal
WMA for Local Agencies; CalAPA SDTC
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Hall Street, St Louis MO - Side by Side
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Hall Street, St Louis MO - 5 ½ Years Later
WMA for Local Agencies; CalAPA SDTC
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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
40WMA for Local Agencies; CalAPA SDTC
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
41WMA for Local Agencies; CalAPA SDTC
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
42WMA for Local Agencies; CalAPA SDTC
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
43WMA for Local Agencies; CalAPA SDTC
Thank you!
Brandon Milar, P.E.
Technical Marketing Manager – Evotherm
925.852.8668