This study investigated the experimental size effect of axial compressive strength of concrete as a function of notch size. Based on the concepts of fracture mechanics and size effect law, theoretical studies for axial compressive failure of concrete specimen under compression have been discussed.
In this study, experiments of axial compressive failure, which mainly failed by Mode I, were performed on cylinder specimens with a notch at center. By varying the notch size, the size effect data of axial compressive strength of concrete were obtained and the results were analyzed by the modified size effect law.
The test results showed an unclear trend in the compression size effect. When the notch size is greater than 4 times the maximum aggregate size, the nominal compressive strength of concrete changed where the expected trend of size effect curve was obtained. We can conclude that the main propagating crack has been sufficiently developed and grew stably. However, when the notch size is less than 4 times the maximum aggregate size, the trend of size effect curve was different. Therefore, we can assume that the main propagating crack has not been developed sufficiently and the crack propagated unstably.