Failure of Layered Sandstone under Brazilian Test Conditions: Effect of Micro-Scale Parameters on Macro-Scale Behaviour

The experimental research in this paper focuses on the effect of micro-scale parameters on macro-scale behaviour of samples tested under Brazilian test conditions for one particular layered sandstone, i.e. sandstone from Modave in the South of Belgium. Five (visually) similar blocks are studied; however, they are different at micro-scale. Their differences on microscopic level (such as grain size, mineral contents and number of layer boundaries) affect the failure process. Fracture length parallel to the layers increases if more layer boundaries (e.g. per cm) are present and more weak minerals. The Brazilian tensile strength of studied layered Modave sandstone is larger for larger quartz grains, while fracture length parallel to the layers is smaller. Quartz grains in the studied layered sandstone are classified as fine sand.