Analysis of the critical stress intensity factor of concrete with gravel and dolomite aggregates tested by different methods

The cracking resistance of concrete is of paramount importance in the context of structural integrity and stability. Therefore, analysing fracture propagation in concrete is essential to evaluate resistance to crack propagation. The critical stress intensity factor ������ is one of the most often used fracture parameters when analysing fracture processes in concrete members. The critical stress intensity factor can be evaluated through standard laboratory tests described in RILEM recommendations. Digital image correlation (DIC) is a new measurement technique that provides the possibility of determining ������ in an alternative way. However, both measurement methods are subjected to certain challenges that may affect the results obtained. The question arises of whether the measurements by the standard RILEM method and by the method based on DIC give comparable results of concrete fracture parameters. The experimental investigation presented in the research paper deals with comparing test results of ������, which were measured by two testing methods. To determine the critical stress intensity factor of concrete, the standard method based on the three-point bend test was applied as the basic testing method, and the ARAMIS 2D system based on DIC was used as a second testing approach. Moreover, aspects such as the influence of the type of aggregate on ������ and whether the type of aggregate would make a difference when assessing the impact of the test method on the results of ������ were analysed.