Investigation of size effect in diagonal?spliting cube tests by nonlinear fracture mechanics theory

One of the methods commonly used in order to indirectly determine the concrete tensile strength value is the splitting tests. In the splitting tests, the specimen size, the type of aggregate and the mix proportions, and the width, thickness and material of the loading line affect the results considerably. Although there are many studies available on the cylinder splitting tests in the literature, there have not been satisfactory studies done on the cube-splitting tests, and the relation between the the cube-splitting tests and other strength values has hardly been analyzed. In this study, the effect of the material and sample size parameters on the concrete tensile strength (especially the diagonal cube-splitting strength) in the cube-splitting has been analyzed in the first place. According to the size effect in concrete fracture mechanics, some decreases occur in the mechanical strength as the size of the sample increases. In this study done by taking all the afore-mentioned ideas into account, the effect of size on the diagonal tensile strength of concrete has been analyzed on the 50mm, 100mm, 200mm samples which have 4mm, 8mm, 16mm maximum aggregate diameters, and which have been prepared with proper concrete mixture according to the Size Effect Law (SEL) approaches. At the end of the analyses, it has been observed that the strength changes with the size effect. The results have been shown with tables and figures.