DESCRIPTION
CEMIX CONCRETE CURE WATER BASED (WB) is a white, low viscosity wax emulsion which incorporates a special alkali reactive emulsion breaking system. This ensures that the emulsion breaks down to form a non-penetrating continuous film immediately upon contact with a cementitious surface. This impervious film prevents excess water evaporation that in turn permits more efficient cement hydration thus reducing shrinkage and increasing durability. The membrane once formed is designed to degrade (via a photonitator in the clear formulation) when exposed to ultra violet light over a period of time dependent on conditions of exposure.
TYPICAL APPLICATIONS & USES
CEMIX CONCRETE CURE WB provides a spray-on temporary membrane to retain moisture in concrete for effective curing. Used for concreting generally, but especially useful for large areas of concrete construction such as runways, motorways or bridgeworks.
ADVANTAGES
- Reduces surface shrinkage and cracking by eliminating moisture loss from exposed areas
- Enables cement to hydrate more efficiently
- Provides hardwearing surface and prevents dusting
- No surface wetting required prior to application to vertical surfaces
- Easy application – reduces labour costs
- Non toxic and non flammable
- Eliminates the need for damp hessian, sand or polyethylene
SUBSTRATE PREPARATION
The surface should be dry and must be free from oil, grease, loose particles, decayed matter, moss, algal growth and curing compounds. For maximum penetration, grit blasting, water blasting or some mechanical means of surface preparation is recommended. Water blasting or an acid wash should be used for the removal of moss or algal growth. Rinse off with liberal quantities of clean water and allow to dry. Protect plants, grass, asphalt, bitumen, plastics and all painted surfaces during preparation and application. Always test apply on an area first and approve look and feel.
APPLICATION
CEMIX CONCRETE CURE WB should be spray applied to the surface of newly placed concrete. The compound should be applied as soon as possible after the concrete is free from surface water. The nozzle of the spray should be held approximately 450mm from the concrete surface and should be passed back and forth to ensure complete coverage. The pump pressure should be maintained at a level producing a fine spray.
Note: Do not use CEMIX CONCRETE CURE WB for any concrete work receiving subsequent coatings or renders. CEMIX CONCRETE CURE WB should not be continuously re-circulated through high shear gear pumps when used in concrete train application. If continuous re-circulation is essential the sprayer should be fitted with a low shear diaphragm pump. Rate
of application depends on requirements but is typically within the range 169 - 270ml/m2 (6.0 - 4.0m2/l).
TECHNICAL DATA
- Appearance – White liquid
- Application Temp – 5 – 30ºC
- Packaging – 5L, 20L & 210L.
- Viscosity – Brookfield Model RVF N1/S10 at 20ºC both grades 8-15 cp
- Curing Efficiency – Water loss 0.17kg/m² applied at 245ml/m², which is considerably more efficient than the maximum permissible water loss of 0.55kg/m² in ASTM C309-74 and 0.39kg/m² in U.S. Federal Specification TT-C-800A. 86% when applied at 270ml/m², Modified Department of Transport Specification for Road and Bridge Works: Clause 2709. Membrane breakdown: After a period of approximately 28 days, the film formed on the concrete surface will begin to degrade. The rate of degradation will depend upon initial membrane thickness and the degree of exposure to ultra violet light Specific Gravity - 0.98 - 1.00
The data shown above reflects
typical results based on laboratory testing under controlled conditions. Reasonable variations may occur on site.
LIMITATIONS
Will break down in time
dependent on exposure to weather. Any remaining film may impair application
of subsequent coatings and should be removed first.
CLEANING
Equipment should be cleaned with solvent immediately after use. Any spillages should be absorbed with sand or sawdust etc. and disposed of in accordance with local regulations.
STORAGE / SHELF LIFE
CEMIX CONCRETE CURE WB has a shelf life of six (6) months when stored at temperatures between 4ºC - 35ºC. Containers should be kept airtight to prevent surface evaporation. Freezing or prolonged exposure to direct heat or sunlight must also be avoided.
