An experimental study of basalt aggregate concrete according to different size effect laws

Concrete brittleness is an important problem in civil engineering applications. Defects such as cracks and voids that occur during the production phase of engineering materials or due to different factors take up more space in large samples and have a negative effect on the overall strength. In experimental studies conducted with concrete, it has been observed that small-sized samples generally exhibit higher strength values, while these values decrease in large-sized samples. In order to examine the strength loss, the principles of fracture mechanics should be utilized. In studies conducted so far, the number of studies that have performed size effect analysis is quite low, and no research has been found on how much volcanic rocks are affected by the size effect. The aim of this study is to examine the use of basalt aggregates in concrete in accordance with the laws of fracture mechanics. In the experimental study, crushed basalt aggregates with size ranges of 0–5 mm, 5–11.2 mm, and 11.2–22.4 mm were used to produce concrete in different dosages. Using the maximum loads obtained by splitting-tensile tests of similar geometric cube samples in three different sizes (50 mm, 100 mm, and 200 mm), they were analyzed within the framework of the fundamental theorem of size effect laws. In addition, the analysis results were examined according to the modified size effect law, and formulas for estimating splitting-tensile strength were proposed and compared with the obtained past test data. Basalt, which can be easily found in certain regions, is important in terms of its use as aggregate in concrete and the supply of durable material.