Strength Variation of Augen Gneiss in the Point Load Test under Different Loading Direction and Temperature

The anisotropic nature of rock strength varies with the degrees of an anisotropic plane. The study on strength index which are effect by anisotropic plane with different loading angle, the role of grain size of mineral and thermal behaviour in the point load index test. The rock material with the heterogeneous mineral of the dark and white bands of mineral with a different grain size that increases the foliation degree and reduced the strength value depends on grain size and their bounding. In Augen Gneiss the strength index depends on the anisotropy plane of the sample with loading direction, thermal variation, and fracturing pattern are controlled by the grain size of the mineral. The microcrack developed with temperature increases and the crack initiated with grain boundaries, and further developed intercrystalline crack with temperature increases. There is no significant difference in density up to 300° c when the natural moisture content is less.