Stabilised sulfate-rich clay with magnesium oxysulfate cement

ABSATRACT Magnesium oxysulfate cements are modern green air-hardening magnesia-based cementitious materials that were produced using the chemical reaction of magnesium sulphate (MgSO4), magnesium oxide (MgO), distilled water and a small number of additive materials. In this paper, the influences of thawing and freezing cycles on the chemical-mechanical and microstructural properties of stabilised sulphate-rich clay with MOSC using a triaxial cell set-up, scanning electron microscopy and X-ray diffraction were investigated. The sulphate-rich clay specimens with various dosages of Magnesium Oxysulfate Cement (MOSC) and different curing times were exposed to one, two and three thawing and freezing cycles in soaked and un-soaked conditions. The consequences showed that the compression strength and behaviour of the stress and strain samples significantly depend on the amount of MOSC. The durability index which was described as the ratio of the resistance before and after stabilising revealed that the durability augments by the increase of MOSC. In addition, increasing curing times in the MOSC stabilised specimens leads to an increase in their compression resistance.