A transparent, gel type composition colour tinted to assist application.
- Easily applied by brush to all formwork types
- Weather resistant Single coat application
- Concrete can be applied immediately or later
- Non staining
- Water based with no flammable or toxic constituents
- Any residue on formwork is easily removed
- Can be used on vertical surfaces
Suretard Gel has been formulated to retard the set of fresh concrete that comes into contact with it. It is ideally suited to the production of exposed aggregate finishes or 'keyed' surfaces for construction joints or for subsequent application of plasters or renders. It is coloured to give a visual indication of where it has been applied.
Best results are achieved on a mould face that is clean, dry and free of any deposits, with uniform absorbency. To facilitate cleaning of mould after stripping it is recommended that a very light mist coat of Release Agent be applied to the mould face and allowed to dry thoroughly before application of Suretard GEL.
It is possible that on prolonged storage partial separation of the constituents may have occurred; therefore it is advisable to lightly stir the material before use. Apply uniformly by brush or roller in temperatures above freezing
Concrete may be placed immediately if care is taken to avoid displacing the Suretard Gel, if left it will dry to produce a surface that is resistant to rain.
After use care should be taken to remove all traces of the Suretard Gel by washing, prior to reuse.
A typical coverage of 3-4 square metres per litre. Actual rate will depend on surface texture and porosity
On horizontal pours the concrete should be placed evenly across the surface. If the concrete is poured from one end only and moved across the face a heavy scouring action results which could remove retarder from the mould face. On vertical pours the mould face should be protected from concrete splashes. This is best achieved by use of a tremie or a sheet placed in the mould and withdrawn gradually as level of concrete rises.
Time before stripping is dependent upon the numerous factors which affect the rate of hardening of concrete. In general stripping should be within 1-2 days. For longer periods or where an accelerated method of hardening is adopted tests should first be made on trial panels to establish the optimum stripping time.
Removal of Retarded Matrix
Contact with the air stiffens the surface of the retarded sand/cement matrix. Therefore removal of the matrix should be as soon as possible after stripping of mould. The stiffening factor can be used to reduce depth of aggregate exposure by delaying removal of matrix for a period established by trials. Removal of retarded matrix should be by low pressure water jetting and broom or wire brushing in two directions at right angles to each other.
Cleaning Equipment and Moulds
Clean brushes and rollers immediately after use with water. Any retarded matrix adhering to mould face should be removed as soon as possible by first softening with water and then scraping with a flat bladed scraper or similar.