Effect of specimen size on fracture energy and softening curve of concrete: Part I. Experiments and fracture energy

The fracture energy of concrete GF is a fundamental fracture parameter, presenting the concrete's cracking resistance. However, because of the experimentally observed size dependency, it remains controversial as to whether the fracture energy can be considered as a material property. In this study, a three-point bend test for a notched beam and a wedge splitting test were performed with different size specimens for ten different concrete mixes in order to investigate the effect of specimen size and geometry on the fracture energy. A data processing method was proposed for averaging the test results of companion specimens, and the fracture energy was calculated from the averaged results. From a comparison of the fracture energies, it was found that the fracture energy increases with an increase in specimen size in both the beam and wedge splitting tests.