Streamlining Asphalt Mixture Dynamic Modulus Testing for Determination of Cyclic Fatigue Index Parameter (S_app) Based on the Simplified Viscoelastic Continuum Damage Model

Abstract

As balanced mixture designs move forward, obtaining index properties quickly will become critical to routine application. This paper details a study into streamlining performance tests so that users may make decisions on as-designed and as-built material in a shorter period. This study is unique to asphalt materials research through its use of the Scrum methodology. Scrum is a form of the Agile project management technique often used in software development to manage complex projects. This process can also address the intricacies of applied research, with a focus on delivering high-value products through an iterative procedure. This paper is focused on optimizing temperature–frequency combinations in dynamic modulus (| E*|) tests to generate an equivalent master curve more rapidly. Three different versions of | E*| tests were conducted on four mixtures using combinations of five temperatures and seven frequencies in an asphalt mixture performance tester (AMPT). Cyclic fatigue testing was also conducted, which allowed for computation of the apparent damage capacity ( Sapp). The results for Sapp show that there is no statistical difference between the three versions. Also, analysis showed that the total testing time for | E*| can be reduced by half without significant changes to master curves and values of Sapp generated under the testing sweep prescribed in the test standards. A streamlined testing version is provided based on a predefined evaluation approach to ensure adequate equivalency of critical parameters from the full testing suite.