This document summarizes information from a California workshop on warm mix asphalt, recycled asphalt pavement, and recycled asphalt shingles. It provides data on usage rates for WMA, RAP, and RAS from 2009 to 2011 according to NAPA surveys. Usage of WMA, RAP, and RAS is increasing. Challenges discussed include developing standardized mix design processes, improving plant efficiencies, addressing laboratory tests that contradict field performance, reducing cracking potential at higher recycled material contents, training on mix design for recycled materials, and handling procedures for RAP and RAS.

1. 1
California WMA Workshop
June 26-27, 2013

2. 2
Overview
WMA
RAP
RAS
Combinations

3. 3
Sources of Info for WMA
 NAPA Survey for WMA, RAP, RAS for years 2009,
2010, and 2011
 NAPA: WMA Best Practices Manual
 First and Second International Conference on WMA
 NCAT website: ncat.us
 warmmixasphalt.com
 WMA producers

4. 4
Estimated WMA Production
0
5
10
15
20
25
30
35
2009 2010 2011
WMAUsage(%)
State
Other Govt.
Non-Govt.
77.9%
19.6%
2.3% 0.2%
Water-injection foaming
Chemical additive
Foaming additive
Organic additive

5. 5
WMA in 2011 (NAPA)

6. 6
Challenges for WMA
1. Keeping track of new WMA Technologies
2. Definition of WMA
3. Developing a Mix Design Process that
works for all WMA Technologies
4. Improving plant burner efficiencies
5. Lab tests that contradict field
performance

7. 7
RAP usage in US (NAPA)

8. 8
RAP Usage (NAPA)
Year RAP Usage
2009 16%
2010 18%
2011 19%
Goal 25%

9. 9
Challenges for higher RAP contents
1. Determining the best way(s) to reduce
cracking potential
2. Training mix designers and specifiers on
use of high RAP content mixes
3. RAP handling procedures especially for
higher RAP

10. 10
RAS usage in US

11. 11
RAS usage (NAPA)
RAS Usage
Year (Thousand tons)
2009 701
2010 1099
2012 1192

12. 12
Challenges for RAS
1. Determining the best way(s) to reduce
cracking potential
2. Getting more states to allow RAS
3. Training mix designers and specifiers on
use of RAS mixes
4. RAS handling

13. 13
Questions ?