The modified silicates in Blockade react chemically with the free calcium ions (free lime) in the cured concrete matrix to create calcium silicate hydrates within the pores and cracks in the concrete. These stable, inert, crystal-like compounds become a permanent non-wearing integral part of the concrete sealing capillaries against the ingress of water and other foreign matter providing a permanent waterproof barrier. In turn, this chemical reaction also dramatically hardens and protects concrete and other cementicious products.

The chemical formula of Blockade allows the sprayed product to form a gel, which is then absorbed into concrete up to depths of 20mm (after suitable watering schedule) and has the ability to bridge leaking cracks up to 2.0mm. This applies most importantly to rooftops where thermal stress is a very high risk factor. This barrier protects against water and chloride ions.

Recommended Uses:

Surface Preparation

Surface to which Blockade is to be applied must be free of dirt, oil, grease and surface contamination. Surface shall be free of water puddles and condensation. Blockade must be applied to clean, dry, dust free concrete surface at least 28 days old. Renders can be treated after 7 days.

Contrary to the above, Blockade can be applied to new concrete once dry enough to walk on, to provide a very effective curing compound.

Curing compounds should not be present in materials. Any materials which prevent penetration should be removed. Where segregation or voids are apparent, chip out, treat with Blockade, and then make good with cementitious materials.

Note: Protect glass, aluminium, wood stains and painted metal surfaces from overspray.

Application

Blockade is best applied by means of a low pressure sprayer such as a nap sack type sprayer at between 20 to 30 psi.
Do not use high pressure spray equipment as this will atomise the product preventing it from performing its function.
Shake well before use.
Locate all cracks and flood with solution ensuring they are filled with product.
Note: For treatment of structural and active cracks refer: Blockade Technical Handbook.
Apply the solution to the remaining area at a rate of between 4-6 square metres per litre.
When surface becomes touch dry - (generally 2-6 hours depending on wind conditions and ambient temperature) flood spray the treated areas with water.
Next day - 24 hours later, water again.
Next day - 24 hours later, water again.
After the final watering, it is recommended to flood the area with water and allow to pond for a minimum of 12 hours to verify that a waterproof seal has been achieved.

Should the 'Blockade treated surface' be effected by rain before the surface has become touch dry, it will be necessary to re-coat the surface once dried out.

Coverage

Coverage depends on the porosity of the concrete as a guide on new concrete an application rate of 5m2 per litre is recommended.
Water 1 hour after application and then again at 24 and 48 hour intervals.

Concrete older than 3 years

In situations where the concrete is more than three years old or it is likely that the 'free lime' has leached out, the second watering should be substituted with an application of Reactor 25 at the rate of 5m2 per litre.

Properties

- Non Toxic
- Biodegradable
- Specific Gravity: 1.212 @ 25°C
- pH: 11.0
- Flash Point: no true flash point
- Hazardous chemicals: Sodium Silicate (modified)

Resistant To:
Mineral and organic acids, oil, grease and water

Packaging
Blockade is supplied in 20 or 200 litre drums. Shelf life is indefinite but protect from direct sunlight.

Caution

Although Blockade is generally non-hazardous and safe to use, the product is highly alkaline, can be severely irritating if swallowed, corrosive to the eyes and can cause irritation to sensitive skin.

Clean off with water, if splashed in eyes flush with water immediately until irritation subsides.

Avoid contact with glass, aluminium, wood stains and painted metal surfaces.

The information presented in this data sheet does not imply any warranty. Further, the maker reserves the right to alter the product, the specification and/or the application techniques as described herein without prior notice, in line with his policy of technological advancement and product improvement. Whilst any information and/or specification contained herein is to the best of our knowledge, true and accurate, no warranty is given or implied in connection with any recommendations or suggestions made by us or our Representatives, Agents or Distributors as conditions of use and any labour involved are beyond our control.