Concreteisaquasi-brittlematerialexhibitinglowstrengthundertension. Thepresenceofa notch or crack can significantly reduce the material’s fracture properties due to stress concentration at the notch tip and the formation of the fracture process zone (FPZ). In the FPZ, microcracks are formed which coalesce to form macrocracks…
Concreteisaquasi-brittlematerialexhibitinglowstrengthundertension. Thepresenceofa notch or crack can significantly reduce the material’s fracture properties due to stress concentration at the notch tip and the formation of the fracture process zone (FPZ). In the FPZ, microcracks are formed which coalesce to form macrocracks and eventually leading to failure. Existing literature shows that the size of pre-existing notch in concrete can significantly affect the strength and cracking behaviour. In order to study the effect of the notch size on the fracture behaviour of plain concrete, a series of wedge-splitting tests (WST) are conducted on specimens with different notch-to-depth ratios. Using acoustic emission (AE) and digital image correlation (DIC) methods, the fracture characteristics of concrete specimens with various notch sizes are studied. Throughout the loading process, AE mea- surements are employed to capture the acoustic emission events, providing details on the position and time of crack initiation and propagation. The crack mouth opening displacement (CMOD) and crack tip opening displacement (CTOD) of the specimens are calculated using DIC measurements to examine the deformation and strain fields on the surface. The findings reveal that, with increasing notch size, the size dependent fracture energy of concrete decreases. The AE analysis demonstrates that there is not much change in the number of events or acoustic energy with change in notch depth, indicating that the mechanisms of fracture remains the same irrespective of the notch size.