Influence of the width of the specimen on the fracture response of concrete notched beams

This work presents an experimental study performed to investigate the influence of the width and size of the specimen on the fracture response of concrete notched beams. Thirty-eight beams with six cross-sections has been tested using a three-point bending (TPB) test setup, which is designed according to the draft of a report developed by Joint ACI/ASCE 446 Technical Committee. Two depths (70 mm and 150 mm) and three widths (35 mm, 70 mm and 150 mm) of the beam are considered. 3D digital image correlation (DIC) is employed for 18 specimens. The load-deflection response obtained from DIC is compared with the load-deflection response obtained from the readings of two linear variable displacement transformers (LVDT). Load responses, peak loads, strain profiles, and failure modes of TPB tests are presented and discussed. The authors observe that a potential width effect is combined with the well-known size effect. In addition, the evaluation of the fracture energy from the load response might be influenced by the width of the beam. Finally, the strain profiles along the notched cross-section obtained from DIC suggest that the evaluation of the fracture energy from the load response might be misleading.