Influence of Size Effects on Opening Mode Fracture Parameters for Precracked Concrete Beams in Bending

Results of three-point bending tests on three sizes of single-edge-notch (SEN) concrete beams are presented. The beams all had the same width (76.2 mm) and span/depth ratio (3.75) with depths of 102 mm, 203 mm and 305 mm. The fracture energy results show wide scatter but apparent independence with beam depth although not with crack depth. The energy release rate results based on LEFM show strong invariance with crack depth and also are invariant between the two larger beam sizes. Good agreement between results of different methods of data evaluation was obtained.