Description
RHEOFINISH 288FD is a medium viscosity, liquid retarder used for achieving an exposed aggregate finish on concrete by retarding the setting of cement paste in the surface matrix of formed concrete and then removing it. The surface retarder is applied on the formwork to effect retardation of the surface of fresh concrete in contact with the treated forms.
Recommended for
RHEOFINISH 288FD is recommended for all formed concrete where it is desired to obtain an exposed aggregate finish or a keyed surface for a superior bond with subsequently placed concrete or mortar layer. The variable depth of retardation allows considerable flexibility to architects in using different shapes and sizes of aggregate to produce attractive patterns of exposed aggregates on cast in-situ or precast panels.
Features and benefits
| Controlled depth of retardation |
Consistent textured finish. |
| Does not kill hardening process |
No deleterious effect on the core concrete or the strength of the concrete mass. |
Variable depth of retardation |
Scope for producing decorative patterns of exposed aggregates with different shapes and sizes of aggregates. |
| Creates rough texture |
Excellent bond for subsequently laid mortar or concrete layer. Avoids costly surface roughening procedures. |
| Allows smooth form release |
No need for a form release agent. |
Packaging
RHEOFINISH 288FD is available in 25 litre carboys and 205 litre plastic lined drums.
Typical performance data
Typical depth of retardation: 8mm@ 10-12 m² / litre.
Properties
| Supply form |
Medium viscosity liquid |
| Colour |
Deep Green |
Application
Use RHEOFINISH 288FD as supplied after stirring thoroughly. Ensure that the surface of formwork is clean and free from oil, grease, mould releasing agents, water, cement or other loosely adhering materials.
Apply RHEOFINISH 288FD at the recommended rate of application (see Dosage) by brush on the inner surfaces of the formwork at least an hour before the placing of concrete.
Protect the applied surface from rain or other damage. Avoid scouring of the treated form surfaces while using poker vibrators, and minimise the flow of concrete across the treated forms while placing and vibrating concrete.
Strike off formwork within 48 hours of placing concrete and then immediately hose down the treated surface with medium water pressure to wash away the unset cement paste in the surface matrix. Brush away all the loosely adhering materials.
Clean the form surfaces of adhering cement paste immediately after striking off. The debris thus collected should be washed away as cement paste can later set hard making it difficult to remove. The period of surface retardation will be reduced in hot weather and also if air voids are present between the form and concrete face.
The period and the depth of retardation can be increased by increasing the rate of application of RHEOFINISH 288FD.
Note:
- It is recommended that field trials be conducted at different coverage rates on the design concrete mix with site raw materials, to determine the optimum depths of penetration.
- With high alumina and rapid hardening cements the concrete should be deshuttered within 6-8 hours.
Dosage
The rate of application depends upon the depth of retardation desired. RHEOFINISH 288FD applied @ 10-12 m² / litre typically results in a depth of retardation of up to 8 mm. Greater depths of retardation are possible @ 6-8m² / litre. Therefore material requirement is 0.1 litre / m² to achieve approximately 8mm depth of retardation.
Note:
Progressively better results are obtained on plywood and timber moulds as they become impregnated and the operatives become accustomed to working with the release agent. RHEOFINISH 202 in general, may be used over timber moulds. etc., which have been treated with other mould oils, providing excess has been removed.
Shelf life
RHEOFINISH 288FD can be stored for 12 months if stored at temperatures above 5°C in tightly sealed original drums. If found to be frozen, thaw it and reconstitute by stirring.
Precautions
Health: RHEOFINISH 288FD is non toxic but can cause irritation to persons with sensitive skin if exposed. Safety: Wear eye protection and gloves while handling the product. Wash thoroughly after handling. Fire: Not flammable. For detailed Health, Safety and Environmental Recommendations, please consult and follow all instructions on the product Material Safety Data Sheet.
Note
Field service, where provided, does not constitute supervisory responsibility. For additional information contact your local BASF representative.
BASF reserves the right to have the true cause of any difficulty determined by accepted test methods.