The paper presents the results of an experimental investigation aimed at evaluating the time-dependent compressibility of a coarse crushed quartzitic slate, focusing on the effects of the previous loading and hydraulic history. Long-term and large diameter compression tests under oedometer conditions were performed at different relative humidity (total suctions) and vertical stresses but following different loading and hydraulic paths. A finding is that pre-compressing at increasing overconsolidation ratios or pre-soaking the crushed material at constant and elevated stresses leads to the progressive vanishing of long-term deformations.