Effect of mica content on compactability and compressibility behavior of micaceous sand

Abstract

The compactability and compressibility behavior of a soil mass through removal of air or water is majorly dependent on soil-structure, type and rate of loading conditions. The uniqueness of micaceous sand arises from the contribution of fragile/flexible platy mica particles along with hard/stiffer spherical sand particles in deciding the compactability and compressibility behavior through complex geometric arrangements along with resilient nature of mica particles. Presence of large mica particles among sand particles creates large void spaces in soil skeleton due to bridging & ordering phenomena. Bridging & ordering represent the irregular arrangement of sand below mica & regular arrangement of sand above mica respectively. However, finer mica particles can help in reducing void spaces among sand particles through pore filling phenomenon. Thus, micaceous sand shows extensive inconsistencies in compactability/compressibility behavior for varying mica contents. The current experimental investigation was conducted to determine the effect of mica content on compactability and compressibility behavior of micaceous sand by performing series of standard proctor compaction and one-dimensional consolidation tests respectively. The compactability behavior of micaceous sand exhibited initially improved (5%, 10% & 15% mica) and later diminished (20%, 25% & 30% mica) response as compared to pure sand (0% mica). However, the compressibility response (1D consolidation) of micaceous sand showed increasing trend with increase in mica content.