On the anisotropy of the athenian schist and its relation to weathering

The influence of schistosity on the strength of the “Athenian schist” when considering the anisotropy index as derived from point load testing, is examined. Furthermore, the influence of the degree of weathering upon the anisotropic characteristics of the schist is also investigated. Anisotropy index values are found to range between just below 1 and 3 approximately. Low anisotropy values correspond to rock in its very weathered state, higher values are related to less weathered material and there is also a trend for anisotropy to decrease towards sound rock conditions. Point load testing proved a reasonable means for assessing those rock characteristics associated with strength, anisotropy and weathering state, while slake durability testing showed considerable insensitivity towards the latter.