Verification of testing parameters of semicircle notched beam fatigue test

Fatigue testing is commonly conducted using the single-edge notched beam (SENB) test, which is not simple to prepare. With the widely use of Superpvae gyratory compactor with its consistent circular compacted samples, the industry is keen to find ways to utilize these samples in testing. Therefore, the semi-circle notched beam (SCNB) fatigue test setup was introduced. However, there are no justified design criteria and/or standard test procedure to evaluate fatigue life of asphalt mixes using SCNB. Thus, there is a critical need for understanding the effect of the significance of each controlling testing parameters to evaluate Superpave mixes resistance to fatigue cracking using SCNB. In this study, common testing parameters were investigated and the failure point due to fatigue was clearly defined. In addition, when comparing test results to the Asphalt Institute (AI) model, it was found that the cyclic load range of 30% to 60% of the ultimate strength could be utilized as an appropriate range with a loading frequency of 1 Hz, at which test results illustrated that strain rate and loading range lay within reasonable range of AI design guidelines.