RELEASE AGENTS

FOR BITUMINOUS MATERIALS

 

SCOPE

Release agents used to prevent bituminous materials from adhering to interior surfaces of truck bodies shall meet the requirements of applicable Iowa Department of Transportation Specifications.

 

ACCEPTANCE

 

Acceptance of release agents for use on Iowa Department of Transportation projects is based on manufacturer and brand name approval. Approved manufacturers and brand names are listed in Appendix A.

 

MANUFACTURER & BRAND NAME APPROVAL

 

Manufacturer shall provide product information and a copy of product evaluation report issued by the National Transportation Product Evaluation Program (NTPEP) to the Office of Materials in Ames, Iowa. The NTPEP report includes the test result per AASHTO TP102, Standard Practice for NEPEP Evaluation of Asphalt Release Agents.

 

Product approval is based on satisfactory evaluation of the NTPEP test report. To obtain approval, an asphalt release agent shall meet the following criteria:

 

         Does not strip at full and diluted strengths per the Seven-Day Asphalt Striping Test,

         Retain ≤ 10.0 grams of HMA after three repetitions for the Mixture Slide Test, and

         Does not fail after 3 pours for the Asphalt Performance Test.

 

Approved products shall not contain flammable materials, solvents, or petroleum elements.

 

MONITOR SAMPLING & TESTING

 

The Office of Materials may sample and test release agents to verify compliance with specifications. Samples will be tested according to AASHTO TP102, the Seven-Day Stripping Test or Iowa Laboratory Method 632. For the Method 632, the release agent shall not alter the G*/sin (delta) results of the asphalt by more than 15%. Products failing the test will be removed from Appendix A.