Title: WHRP Project 0092-10-06 Effect of Recovered Binders from Recycled Shingles and Increased RAP Percentages on Resultant Binder PG
1 WHRP Project 0092-10-06 Effect of Recovered
Binders from Recycled Shingles and Increased RAP
Percentages on Resultant Binder PG
- Ramon Bonaquist, Ph.D., P.E.
- Advanced Asphalt Technologies, LLC
2Outline
- Objectives
- Approach
- Major Findings
- Conclusions and Recommendations
3Objectives
- Improve the AASHTO performance graded binder
blending chart analysis. - Use the improved blending chart analysis to
evaluate current WisDOT criteria for binder
replacement. - Identify potential effects of using RAP and RAS
on pavement service life, both positive and
negative.
4Approach
- Review of current practice
- WisDOT specs relative to other agencies
- AASHTO M323 blending chart analysis
- Blending chart improvements
- RAS
- Multiple recycled binders
- Characterization of WI recycled materials
- 6 RAP, 6 FRAP, and 6 RAS
- Northern and Southern sources
5Approach Continued
- Reliability based blending chart analysis
- Considered variation in temperature and
continuous grade temperature - Effect of WisDOT binder replacement criteria on
low temperature properties - Recommendations for adjustments
6Review of Current Practice
- WisDOT binder replacement relative to
- Alabama
- Georgia
- Minnesota
- Missouri
- South Carolina
- Texas
- Virginia
7Surface Mixtures
8Lower Layer Mixtures
9Blending Chart Improvements
- Issues
- AASHTO M323 and AASHTO PP53 use linear blending
charts for RAP and RAS - Linear blending charts were developed for blends
of recovered RAP binders in virgin binder. Do
they apply to RAS and blends with RAP and RAS? - Cant grade recovered RAS binders due to
different rheology primarily at low
temperatures. - Fails stiffness at very low temperature
- Fails m-value at very high temperature
10Blending Charts for RAS
11High Temperature
12Intermediate Temperature
13Low Temperature
14Linearity Limit
15Grading RAS Binders
- Extract and recover RAS binder
- Prepare a 30/70 blend of recovered RAS in virgin
binder of known performance grade - Grade blend per AASHTO R29
- Knowing virgin and 30/70 blend continuous grade
extrapolate RAS continuous grade
16Notes on RAS Binder Recovery
- AASHTO T164 Method A, centrifuge extraction
- Rotovapor primary distillation
- Abson recovery
- Modifications
- Heat flask in oven after primary distillation and
prior to start of Abson recovery - Use higher temperatures in Abson recovery
17Blending Chart for Multiple Recycled Binders
18Blending Chart vs R29 High
19Blending Chart vs R29 Intermediate
20Blending Chart vs R29 Low
21Recycled Material Characterization
22RAP/FRAP High
23RAP/FRAP Intermediate
24RAP/FRAP Low
25Average Grade of WI RAP
- PG 82.8 (26.9) -21.8
- Standard Deviation
Property WI RAP Virgin PG 64-22
High 2.2 0.5
Intermediate 1.4 1.1
Low 1.4 0.8
26Extrapolated RAS High
27Extrapolated RAS Intermediate
28Extrapolated RAS Low
29Average Grade of WI RAS
- North
- PG 122.1 (34.4) -4.7
- South
- PG 111.3 (31.0) -8.4
Property WI RAS Virgin PG 64-22
High 5.4 0.5
Intermediate 1.8 1.1
Low 1.8 0.8
30WI RAP vs WI RAS
Property WI RAP North RAS South RAS
High 82.2 122.1 111.3
Intermediate 26.9 34.4 31.0
Low -21.8 -4.7 -8.4
31Reliability Analysis
- Two sources of variability
- Pavement temperature at the project location
- Continuous grade of blended binder
- Overall reliability
32Standard Deviation of Blend
33Standard Deviation of Blend
34Standard Deviation of Blend
Property Virgin RAP RAS
High 0.5 2.2 5.4
Intermediate 1.1 1.4 1.8
Low 0.8 1.4 1.8
35Reliability Analysis
PG 58-34 61 Weather Stations
Mid Grade Binder Exceptional Binder
PG 58-28 79 Weather Stations
36Mid Grade Surface Current Limits
37Exceptional Surface Current Limits
38Mid Grade Surface Revised Limits
39Mid Grade Lower Revised Limits
40Revised Limits
41Conclusions
- Linear blending is applicable to blends of RAS up
to about 30 percent - Linear blending provides a reasonable estimate of
the continuous grade of blends of multiple
recycled binders - WI RAP/FRAP is very consistent having a recovered
grade of PG 82.8 (26.9) -21.8
42Conclusions
- Appears to be a geographic difference in WI RAS
- North 122.1 (34.4) -4.7
- South 111.3 (31.0) -8.4
- RAS changes binder grade much more than RAP
- Current WisDOT binder replacement does not treat
RAP and RAS mixtures equally
43Recommendations
- Consider modifying binder replacement criteria to
provide similar reliability for RAP and RAS
mixtures - Use reliability analysis to approve mixtures with
recycled contents greater than the binder
replacement limits - Monitor continuous grade of recycled sources
using the procedures developed in this project
44Recommendations
- Monitor continuous grade of virgin binder sources
- Monitor cracking performance of pavements with
recycled binders
45Questions/Discussion
Ramon Bonaquist Advanced Asphalt Technologies,
LLC 108 Powers Court, Suite 100 Sterling, VA
20166 703-444-4200 aatt_at_erols.com