Monday, 16 October 2017

Wisconsin

Wisconsin Shingle Recyclers

Wisconsin Department of Transportation (WisDOT), together with the Wisconsin Asphalt Pavement Association and member contractors, conducted a series of field and lab tests in 2008 leading to the adoption of an additional special provisional (ASP) modification to the standard specification that allows the use of RAS in HMA. Effective in January 2009, this new specification is a part of the WisDOT’s Construction Materials Manual (CMM). The RAS specification is included in “Section 460 – Hot Mix Asphalt Pavement:

http://roadwaystandards.dot.wi.gov/standards/stndspec/sect460.pdf

This new ASP-6 specification provides for the use of RAS in combination with various grades of RAP in HMA up to specified limits before a change in the virgin binder grade is required. Subsection 460.2.5 on “Recycled Asphaltic Materials” states:

 

1. The contractor may use recycled asphaltic materials from FRAP, RAP, and RAS in HMA mixtures. Stockpile recycled materials separately from virgin materials and list each as individual JMF components.
2. Control recycled materials used in HMA by evaluating the percent binder replacement, the ratio of recovered binder to the total binder. Conform to the following:

 

Table 6 Asphaltic Material Usage

Maximum Allowable Percent Binder Replacement Recycled Asphaltic Material
Lower Layers
Upper Layer
RAS only
20
15
RAP only
35
20
FRAP only
35
25
RAS and RAP
30
20
RAS and FRAP
30
25
RAS, RAP, and FRAP
30
25

And Subsection 460.2.5 on “Recovered Asphaltic Binders” states:

 

1. Establish the percent of recovered asphaltic binder from FRAP, RAP, and RAS for the mixture design according to AASHTO T 164 using the appropriate dust correction procedure. If production test results indicate a change in the percent of recovered asphaltic binder, the contractor or the engineer may request a change in the design recovered asphaltic binder. Provide at least 2 recent extractions from the contractor's mixture design laboratory supporting that change.
2. The contractor may replace virgin binder with recovered binder up to the maximum percentage allowed under 460.2.5 without changing the asphaltic binder grade. If using more than the maximum allowed under 460.2.5, furnish test results indicating that the resultant binder meets the grade the contract originally specified.”

 

Judy Ryan, WisDOT Research Engineer
608-246-5456

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Last Updated: ( Friday, 29 July 2011 )