Investigation of the multitemperature fracture behavior of asphalt mixtures utilizing DIC technology

This study investigates the fracture damage behavior of asphalt concrete at varying temperatures by analyzing the fracture behavior of semi-circular bend (SCB) specimens. The Digital Image Correlation (DIC) technique is employed in conjunction with load-time curves. Initially, asphalt concrete semi-circular specimens were subjected to loading using a Universal Testing Machine (UTM) at temperatures ranging from -10°C to 50°C. This process facilitated the acquisition of load-time curves, allowing for a comparison of the fracture work across different temperatures. Subsequently, the surface deformation of asphalt mixtures was monitored in real-time at high temperature (50°C), normal temperature (20°C), and low temperature (-10°C) using Digital Image Correlation (DIC) technology. Finally, an in-depth analysis of the cracking damage mechanism of asphalt concrete at varying temperatures was conducted based on the geometric characteristics of cracks and their propagation paths. Studies have demonstrated that asphalt concrete exhibits significant temperature sensitivity. As temperatures decrease, the bearing capacity of the asphalt mixture increases, while the deformation characteristics of the surface before and after peak loading are substantially influenced by temperature. At elevated temperatures, cracks tend to propagate around the aggregates with minimal fracture of the aggregates themselves. Conversely, at lower temperatures, the bearing capacity is enhanced, brittleness increases, and fractures occur directly through the aggregates. This study provides a theoretical reference for understanding the temperature-sensitive properties related to the fracture behavior of asphalt concrete.