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PAPA Regional Technical Meetings
Warm Mix Asphalt (WMA) Implementation
Steven L. Koser, P.E.Chief, Roadway Management
March 14-16, 2016
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Warm Mix Asphalt (WMA)
• What is WMA?
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Warm Mix Asphalt (WMA)
Job‐Mix FormulaComposition Tolerance Requirements of the Completed Mix
Temperature of Mixture (F)
HMA WMA
Class of Material Minimum Maximum Minimum Maximum
PG 58‐28 260 310 215 310
PG 64‐22 265 320 229 320
PG 76‐22 285 330 240 330
From Pub. 408, Section 409 (HMA) and 411 (WMA)
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Warm Mix Asphalt (WMA)
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Warm Mix Asphalt (WMA)
• How do we get to 100% WMA?
• District Plans
• Potential Issues
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WMA Usage – Nationwide
• Nationwide use of WMA• Based on 2014 NAPA
Industry Survey
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WMA Usage – Nationwide
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WMA Usage - PA
Source:
Asphalt Producers Sampled in 2015• Asphalt Producers sampled either with HMA or
WMA = 123 (125 in 2014)• Asphalt Producers sampled with WMA = 86 (63 in
2014)• Percent of Total Asphalt Producers sampled with
WMA = 86/123 = 69.9% (50.4% in 2014)
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WMA Usage - PA
156,301 265,127656,732
1,931,5811,503,804
2,430,863
3,427,285
0
500,000
1,000,000
1,500,000
2,000,000
2,500,000
3,000,000
3,500,000
4,000,000
2009 2010 2011 2012 2013 2014 2015
WMA Usage 2009‐2015 (TONS)
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WMA Usage - PA
0
100000
200000
300000
400000
500000
600000
700000
800000
1‐0 2‐0 3‐0 4‐0 5‐0 6‐0 8‐0 9‐0 10‐0 11‐0 12‐0
Tons of W
MA
District
Increase Use of Warm Mix Asphalt
2013 2014 2015 2016*
*Projections
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Focus Areas: HMA vs. WMA Standard Const.Individual Core Density
Wearing Course Density Data from eCAMMS.
0%
5%
10%
15%
20%
25%
30%
Nor
mal
ized
% o
f To
tal
% Density of Individual Cores - Wearing
2015 Statewide % of HMA & WMA Cores with X% Density [Std. Lots (409A)]
HMAWMA
Meets Specifications
www.dot.state.pa.usWearing Course Density Data from eCAMMS.
Focus Areas: HMA vs. WMA RPS Const.Individual Core Density
0%
5%
10%
15%
20%
25%
30%
Nor
mal
ized
% o
f To
tal
% Density of Individual Cores - Wearing
2015 Statewide % of HMA & WMA Cores with X% Density [RPS Lots (409B)]
HMAWMA
Meets Specifications
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Warm Mix Asphalt (WMA)
Questions?