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The building owner wanted to fix the floor's dusty condition before moving in.
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Cracks developed throughout the floor.

Another is extending the life of the concrete slab by using surface treatments containing certain chemicals, including sodium silicate and magnesium flu silicate. Remember that sealing products will not convert a poor slab into a quality floor. They simply are a means of upgrading a dusty floor while improving its wear resistance.

When using these products, remember that the depth of penetration into the concrete slab will vary with the porosity of the concrete surface and concrete moisture content at the time of application. Products in this group are not specifically formulated for curing applications and do not meet the requirements of either ASTM C 309 or ASTM C 1315 for liquid membrane forming compounds. While they may offer some desirable benefits when you apply them after curing, do not apply them on fresh concrete.

If you plan to apply either of these surface treatments on new concrete floors, moist-cure the floor for at least seven days and allow it to air dry according to the product manufacturer's recommendations. Remove liquid membrane-forming curing compounds before applying the surface treatment, as the membrane could prevent penetration of the liquid. The lone exception would be using compatible curing and sealing products from a single manufacturer.

Consider several specific items before selecting a liquid surface treatment as your solution. ACI recommends determining the anticipated jobsite conditions. And consult with the building's owner to agree on the final appearance of the treated surface.

When a diluted solution of sodium metasilicate (water glass) or silicofluorides soaks into a floor's surface, the silicate reacts with calcium compounds to form a hard, glassy substance within the pores of the concrete. The degree of improvement depends on how deeply the silicate solution penetrates.

For this reason, dilute the solution with water to make it penetrate deeply. Apply three or four coats, allowing the previous coat to dry before applying the next coat. For the first two coats, use four parts water to one part silicate. The third coat should be a 3-to-1 solution applied after the second coat has dried. The treatment is completed as soon as the concrete surface gains a glossy, reflective finish.

Apply zinc, sodium, and magnesium silicofluoride sealers the same way as water glass. Use these compounds individually or in combination, but a mixture of 20% zinc and 80% magnesium gives excellent results.

For the first application, dissolve one pound of silicofluoride in one gallon of water. For subsequent coatings, use two pounds per gallon of water. Mop the floor with clean water shortly after the preceding coat has dried to remove encrusted salts. Because they are toxic, follow all safety precautions when applying silicofluorides.