Fracture Tests of Multiple Specimen Sizes: Mechanical Fracture Parameters of C30/37 Concrete by Inverse Analysis

Abstract

The paper presents a part of the research aimed at developing a comprehensive experimental– computational methodology for determining the values of mechanical fracture parameters of concrete independent of the specimen size and geometry. To this end, laboratory fracture tests in three-point bending and wedge-splitting test configurations were carried out using three different specimen sizes with two well-separated initial notch depths. The test records were used to identify selected mechanical fracture parameters using inverse analysis. Identifications were performed for individual specimens of each test configuration followed by statistical evaluation for individual sizes, notch depths, test configurations and for all specimens tested. The obtained parameters were used in the numerical simulation of the tests and the resulting load vs. displacement diagrams were compared with the experimental ones. The parameters were also analysed in terms of their dependence on the size of the initial uncracked ligament. As expected, a significant dependence of the fracture parameters was confirmed.