Evaluation of Alternative Test Procedures for Cold In-place Recycling Mix Designs

Abstract

For Cold Recycling mix designs, the use of the raveling test (ASTM D7196) in combination with other tests maybe patented by Road Science and their predecessors. Due to uncertainties with the patent on the mix design procedure, many agencies have been reluctant to use the mix design procedure. There is also a concern that the specification value for minimum indirect tensile strength is not as well documented as the more conventional Marshall stability. The two objectives of this study were to determine an alternative test for the raveling test that fit in to the current mix design procedure and verify the specification value for minimum indirect tensile strength to perform the Asphalt Recycling and Reclaiming Association�s (ARRA�s) mix design with confidence. Recycled asphalt pavement (RAP) from three different sources was obtained, along with CSS-1 and CSS-1h emulsions from a previous study and seven new RAP sources, along with CSS-1h emulsions were obtained for the current study. The study incorporated the most promising results from the previous study. However, it could not verify percent retained Marshall stability as an alternative for the raveling test possibly due to lack of temperature control in the asphalt lab. Marshall stability of 1250 lbs was also found to equate with 41.3 psi indirect tensile strength.