Durability of cement-sodium silicate grouts with a high water to binder ratio in marine environments

The results reveal that satisfactory properties and durability, such as a setting time of 60-120 s, a flexural strength reduction of −3-6% after sulphate attack by sea water, a permeability of 1.2-1.6 MPa and an autogenous shrinkage of −0.298-1.22 milli, were obtained in cement-sodium silicate grouts with a w/b of 1.1-1.6 and dosages of sodium silicate of 4.4-5.7 wt%. However, hardened grouts suffered serious deterioration due to sulphate attack in 3 wt% sodium sulphate solutions and fatal drying shrinkage when exposed to air with a relative humidity of 60% at 20 °C. The cement-sodium silicate grout with the recommended composition is feasible and durable in marine environments, but special care must be taken when this grout is applied in environments with a high sulphate concentration or wetting-drying cycles.