Environmental degradation of clayey rocks

Abstract

This paper explores the mechanisms that lead to the degradation of clayey rocks when exposed to environmental effects as those caused by unloading and cyclic variations in relative humidity. The following aspects are evaluated: (i) the number of applied RH cycles, N, (ii) the amplitude of relative humidity cycles, RH, (iii) the stress level (p-ua) and (iv) the effect of the fluid used to induce rock saturation (liquid water or vapour). The implementation of nonconventional experimental techniques for inducing and tracking rock degradation, at 'macro' and 'micro' scales, is described. An experimentally-based framework of behaviour is presented which may be used in practice for the evaluation of the degradation potential of clayey rocks.