Cementitious Coating 851 is a two component, thixotropic, polymer modified, cementitious waterproofing coating. It cures to form a hard, durable, highly alkaline coating with a degree of elasticity which protects concrete and other mineral substrates from the effects of aggressive acid gases and chlorides and water ingress.

Usage & Highlights

• Provides chloride protection on highway and coastal structures and enhances the durability of reinforced concrete.
• Incorporates the latest proven cement chemistry, microsilica, fibre and styrene acrylic copolymer technology.
• Pre-packaged material only requiring mixing on-site.
• Brush, trowel or spray applied normally in two coats. Floors and decks only require a single coat application.
• Excellent adhesion to sound prepared concrete.
• Dense matrix offers low permeability to water at 10 bar positive and negative pressure and very high diffusion resistance to a carbon dioxide gas and chloride ions.
• Provides the equivalent of 100mm of good quality concrete cover.
• Protects concrete in sulphate contaminated ground conditions.
• Non-toxic when cured and listed as authorised for use under Regulation 31 for use in the supply of drinking water.
• Easily overcoated with specialist membranes to provide further protection and aesthetic properties.

Surface Preperation

The areas to be treated must be free from all unsound material, dust, oil, grease, corrosion by-products and organic growth. Smooth surfaces should be roughened, all loose material and surface laitance removed and reinforcement cleaned to bright steel using wet grit blasting techniques or equivalent approved methods. The strength of the concrete sub-base should be a minimum of 20MPa. The prepared substrate should be thoroughly soaked with clean water until uniformly saturated without any standing water.

Application

Cementitious Coating 851 is applied using brush, trowel or spray techniques. Care should be taken to ensure that air is not entrapped onto the surface. For vertical and overhead applications, apply in 2 x 1mm thick coats, applying the second coat when the first coat is stable but not fully set (typically 30-60 minutes depending on temperature). On horizontal applications (floors, decks, etc.) apply in a single 2mm thick layer, spreading with a notched trowel, squeegee or skid leveller, and immediately use a spiked roller to remove entrapped air.