This study investigates the influence of redispersible latex powder and hydroxy propyl methyl cellulose on the physical and mechanical properties of cement-sodium silicate grouts with a high W/B ratio. The rheological properties, setting time, compressive strength, autogenous shrinkage sulfate attack resistance and permeability of the grouts were assessed and compared. The microstructures were investigated in terms of crack development. The results show that satisfactory properties and durability, such as an initial setting time extension of 20~55%, an autogenous shrinkage reduction of 0.332~1.21‰, and a permeability addition of 0.1–0.4 MPa, were obtained in cement-sodium silicate grouts with the addition of two polymers. The flexural strength of cement-sodium silicate grouts with redispersible latex powder was improved after curing in water and sulfate attack by 3 wt% sodium sulfate. However, the addition of two polymers reduced the compressive strength of all grouts except for the redispersible latex powder content of 3%. These research results can provide a technical reference for grouting material selection and mixing ratio adjustment.

Keywords: Cement sodium silicate grout, Redispersible latex powder, Hydroxy propyl methyl cellulose, Physical and mechanical properties, Microstructure