Liquid Densifiers: An Aqueous solution of SiO2 dissolved in the respective Hydroxide (see below) that penetrates into the concrete surface and reacts with the Calcium Hydroxide to provide a permanent chemical reaction that hardens and densifies the wear surface of the cementitious portion of the concrete.
- Sodium Silicate
- Potassium Silicate
- Lithium Silicate
- Alkalis solution of Colloidal Silicates or Silica
All the above is the same chemistry varying only by the alkali used for solubility of the SiO2.
1. The following products do not harden or densify concrete.
- Siliconate is a synonym for Sodium Silicate that is a solid without any water and therefore non-reactive in the reactions described above.
- Colloidal Silica SiO2 that is suspended only in H2O is non-reactive as a densifier.
- Siliconates are sometimes a truncated descriptions for a Alkyl (organic) Alkali Metal Silicate which are water repellents and react in the acid form of CO2 (Carbon Dioxide) and H2O (Carbonic Acid). These might be used as an additive in Silicate Solutions for early water repelling of the densifiers.
Definition of Sealer from ASTM D16: A liquid composition to prevent excessive absorption of finishing coats into porous surfaces; also a composition to prevent bleeding.
- Sealer-Semi Impregnating Stain Protection: A film forming material which will penetrate into the polished and densified concrete leaving a protective surface film of less than 0.5mils which meets the OSHA requirements for slip resistance as tested by ASTM D 20471, and Stain resistance of ASTM D 13082.
- Sealer-Impregnating Stain Protection: Non-film forming stain and food resistant penetrating sealer designed to be applied to densified and polished concrete. Material must meet the requirements of OSHA for slip resistance as tested by ASTM D 20471, and Stain resistance of ASTM D 13082.
1. ASTM D2047 - Standard Test Method for Static Coefficient of Friction of Polish-Coated Flooring Surfaces as Measured by the James Machine.
2. ASTM D1308 - Standard Test Method for Effect of Household Chemicals on Clear and Pigmented Organic Finishes.
“With the establishment of these standardized definitions, contractors, owners and architects can communicate more clearly about the desired surface and necessary processes,” said Brad Burns, Executive Director, CPAA. “The result of the standardization will be a higher quality end product.”
The full list of industry leading terms and definitions used with processed and polished concrete can be found here: http://www.concretepolishingassociation.com/glossary.php.