Abstract: “In order to improve the properties of Magnesium Oxysulfate (MOS) Cement, the effects of Citrate and Sodium Silicate with single or double-doped way on water resistance and mechanical strength of MOS cement were investigated. Also scanning electron microscope (SEM) technique was adopted to explain the morphology of phase composition. The experimental results showed that under the condition of 15±3°C，RH=70±5% single Citrate increasing improve the compressive and flexural strength of MOS cement while exert less effect on water resistance of MOS cement. The double-doped Citrate and Sodium Silicate by the mass ratio of 1:2 could both increased 7d flexural strength by twice and compressive strength by 50% and simultaneously largely improve water resistance of MOS cement. SEM results showed that a large number of connected wheat-like-needle hydration products were formed in hardened MOS cement paste with double-doped Citrate and Sodium Silicate.”

Keywords: Magnisium Oxysulfate Cement; Sodium Silicate; Citrate; Water Resistance; Mechanical Properties