(1) Strong adhesion and high strength. After solidification and hardening of sodium silicate, the main components are silica gel and silica. Silicate gel can block capillary flow gap and prevent water infiltration, so it has high adhesion and strength. Engineering practice has proved that the compressive strength of concrete prepared with water glass can reach 15 ~ 40 MPa. (2) Excellent acid resistance. Because the main component of water glass after hardening is silicon dioxide, it can resist almost all organic and inorganic acids except hydrofluoric acid and overheated phosphoric acid. It is a building material with excellent acid resistance and can be used to prepare acid-resistant concrete, acid-resistant mortar and acid-resistant mortar.
(3) It has good heat resistance. After hardening, the water glass forms a mesh skeleton of silicon dioxide, which does not burn or decompose at high temperature, and its strength is improved. Can be used for preparing heat-resistant concrete, heat-resistant mortar and heat-resistant cement.
(4) Poor alkali resistance and water resistance. After sodium fluorosilicate is added to water glass, it can't be completely hardened, and there is still a certain amount of Na20.nSi02. Because of Na20. SiOZ and SiO _ 2 are both soluble in alkali, while Sioz and SiO _ 2 are soluble in water. After hardening, the alkali resistance and water resistance of water glass are poor. In order to improve the water resistance of water glass, the hardened water glass is usually treated with medium concentration acid.