In this research, the mechanical and fracture behaviours of concrete containing waste CD shreds were investigated using the three-point bending notched beam test, according to RILEM recommendations. The size effect of waste CD shred on concrete properties was the focus of this research. The study indicates that the fracture energy and modified characteristic length were found to increase significantly with increasing the size and volume fraction of CD shreds due to anchoring and bridging effects. In other words, concrete with higher amounts and larger sizes of CD shreds exhibit higher cracking resistance and the brittleness decreases accordingly. However, the strength properties were found to decrease when concrete with larger portion and size of CD shreds.