Method of increasing density and strength of highly siliceous cement-based materials

摘要

High-strength, high-hardness concrete, mortar, or grout is prepared by blending portland cement, water, and aggregate with a source of reactive silica, pouring the concrete mixture into a form, allowing the concrete to cure until it reaches its conventional 28-day strength, and immersing the cured concrete in a solution of alkali metal hydroxide and aluminum nitrate at 60 DEG -110 DEG C. for 3-14 days. Alternatively, the cured concrete may be sprayed with the solution and maintained at 60 DEG -110 DEG C. for 3-14 days. A dense, hard surface layer of alkali metal aluminum silicate is formed, the compressive strength and surface hardness of the concrete is increased, and the water infiltration rate into the concrete is decreased.