Characterization of the fracture mode in asphalt at varying temperatures

ABSTRACT: Cracking is a primary mode of distress in asphalt pavements that is generally caused due to repeated traffic loadings, exposure to temperature fluctuations, aging or reflection of cracks in underlying layers. Such cracking can readily lead to higher maintenance and rehabilitation costs for pavement infrastructure, hence negatively affecting the economy both directly and indirectly. To prevent excessive cracking, it is important to understand the cracking characteristics of asphalt mixtures for implementation in road, airport and port pavements. This study aims to investigate the effect of loading and temperature on the cracking behaviour of asphalt using the Indirect Tensile Test (IDT), along with high-speed photography analysis techniques. The results indicate that cracking can occur prior to the asphalt reaching its peak strength in the IDT test. Furthermore, it was observed that increasing temperature can cause a decrease in the peak strength of the asphalt samples and change its fracturing behaviour as well.