Dynamic semicircular bending testing for asphalt mixture fatigue evaluation

Abstract

Determining the fatigue life of asphalt mixtures is an important step in predicting the performance of flexible surface courses, and it is necessary to use laboratory tests that adequately represent the mechanisms that lead to the failure of mixtures due to fatigue. Currently, methods such as Indirect Tensile Test (IDT), Four-Point Beam Bending (4PB) and Direct Tension (DT) are used for this purpose. Due to their practicality and speed, static fracture tests such as Semi-Circular Bending (SCB) are also widely used, but they do not allow fatigue life to be determined. This study aims to investigate the viability of the dynamic SCB test as an alternative for obtaining fatigue life coefficients in order to optimize the analyses required for the mechanistic-empirical design of sidewalks. Initially, two systematic mappings were carried out to support the methodological decisions. Static and dynamic SCB tests and IDT fatigue tests were then carried out on two asphalt mixtures. The results were statistically compared to assess the agreement between the methods and indicated that, although there were differences in the fatigue curve coefficients obtained by the dynamic SCB and IDT tests, this was not statistically significant and both had similar fatigue performance ratings. This suggests that dynamic SCB tests are an interesting tool for evaluating fatigue and can optimize asphalt pavement design. The study highlights the importance of developing simplified and effective test methods to ensure sustainability, efficiency and safety in transportation infrastructure projects.