Fracture assessment of small and large-scale steel fibre reinforced concrete specimens using acoustic emission and digital image correlation techniques

The fracture assessment of concrete and concrete composites using Digital Image Correlation (DIC) and Acoustic Emission (AE) techniques is commonly performed on small-scale laboratory specimens, with findings then extrapolated to large-scale structures.DIC provides detailed surface displacement and macrocrack visualization, while AE offers real-time tracking of micro and macro cracks.However, in real-world scenarios, factors such as structural geometry, variations in loading and background noise can significantly affect AE and DIC data, making interpretation challenging.This study examines small-scale standard notched Steel Fiber Reinforced Concrete (SFRC) beams and large-scale precast SFRC tunnel segments under three-point bending (3PB) to conduct a comparative analysis of fracture behaviour.The influence of tunnel geometry, casting methods, and loading conditions on fracture behaviour is emphasized.The similarities and differences in fracture mechanisms between small-scale beams and large-scale tunnel segments are identified.