Characterization of asphalt mixture's fracture resistance using the semi-circular bending (SCB) test

Abstract

Pavement cracking is a major distress mode in asphalt pavements. The fracture resistance is an important factor that relates to pavement cracking. This paper describes the evaluation of the fracture resistance of asphalt mixtures using the semi-circular bending (SCB) test. The mechanism of the SCB test is based on the elastic-plastic fracture mechanics concept that leads to the laboratory determination of the critical strain energy release rate, also called the critical value of J-integral (Jc). Asphalt mixtures from nine rehabilitation field projects throughout the state of Louisiana were evaluated in this study. The critical strain energy release rate of plant produced-laboratory compacted (PL) asphalt mixtures was evaluated using a three-point SCB test. In addition, field cracking measurements for those projects that have been trafficked for approximately ten years were performed. Four types of asphalt binders and two nominal maximum aggregate sizes were included in those mixtures. Analysis of the results indicated that there is a good correlation between the critical values of J-integral (Jc) and the field cracking rate. The Jc value increased as the cracking rate decreased. Results of this studysupport to use the semi-circular bend test to evaluate the fracture resistance of asphalt mixtures. © RILEM 2012.