Properties of sepiolite clay soil as a natural material (Iran’s sources clay)

Abstract

ABSTRACT Sepiolite is a fibrous clay mineral, which is mostly associated with a semi-arid to arid climate, with characteristics intermediate between kaolinite and montmorillonite minerals. An experimental study was conducted, with the goal of creating a substantial database of physical, microstructural, and geotechnical characteristics of sepiolite to develop its applications as a natural resource that is explored as the main deposit of Iran. It has been found that sepiolite soils were lightweight, porous, and cohesive with negligible settlement and swelling properties and almost high UCS values. Various analysis were performed to characterise the macroscopic behaviour (Atterberg limit, physical, and compressibility tests), microstructural, chemical, and mineralogical characterisations by chemical analysis, X-Ray diffraction, and Scanning Electron Microscopy. At first glance, sepiolite soils showed high liquid limits with medium to high plastic indices which can result in problems including creation of up and down movements in foundations. After mixing with silt and fine sand to decrease high liquid limit and optimum moisture amounts, sepiolite is suitable candidate for engineering applications (including clay liners, clay cores, etc.) due to its compressibility and strength characteristics. In conclusion, sepiolite soils are strongly recommended for geo-environmental structures due to their adsorption capacity, low permeability coefficient, and suitable strengths.