Paper contribution

Slaking sensitivity of rocks – insights from a multi laboratory parameter study

Markus Kaspar; Christine Latal; Gerhard Pittino

Proceedings
EUROCK 2026
Pages
331-336
Submitted
28 January 2026
Accepted
15 June 2026
Published
12 August 2026

Summary

Abstract

The slaking behaviour of rocks is of geotechnical importance, affecting the stability of slopes and excavation pits, for example, as well as influencing the performance of underground excavation works, such as clogging of TBMs. Traditionally, wetting-drying and slake durability tests are performed to assess the degradation behaviour of weak rocks. Depending on their genetic origin, the slaking and disintegration behaviour of these rocks may exhibit different patterns. This study uses the results of widely used slaking tests, combined with the characterisation of disintegrated materials/decay products, to propose a tool for evaluating slaking sensitivity. Combining and extending the evaluation of these tests with mineral composition data and mechanical parameters enables a more detailed evaluation of the slaking behaviour of weak and soft rocks. Sedimentary rocks exhibit strong static slaking, whereas weak rocks derived from crystalline rocks slake under dynamic conditions. These findings have wider implications for estimating rock degradation in different geological settings and offer a quick laboratory method of estimating slaking rates and the potential liberation of fines, for example in the event of extreme precipitation.

Contributors

Authors

  1. Markus Kaspar Graz University of Technology, Austria ORCID 0000-0002-4174-2997
  2. Christine Latal Graz University of Technology, Austria
  3. Gerhard Pittino Chair of Subsurface Engineering, Montanuniversität Leoben, Austria

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Works cited

References

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