Description
RHEOBUILD 850 is formulated from synthetic polymers specially designed to impart rheoplastic qualities to concrete.
A rheoplastic concrete is a fluid concrete with a slump of at least 200 mm, easily flowing, but at the same time free from segregation and having the same water/cement ratio as that of a low slump concrete (25 mm) without admixture. RHEOBUILD 850 is chloride free.
Advantages
RHEOBUILD 850 considerably improves the properties of fresh and hardened concrete.
Primary uses
- Microsilica concrete
- Mass concrete pours
- Ready mixed concrete
- Long-distance transport
- Pumped concrete
- Casting in hot climates
To obtain:
- Reduced thermal peaks
- High workability for longer periods
- Lower pumping pressure
- Delayed setting with longer workability
- Higher ultimate strengths.
- Reduced permeability
- Improved durability
Compatibility
RHEOBUILD 850 is compatible with all cements and most air entraining agents meeting the ASTM standards. The addition of RHEOBUILD 850 and MICRO-AIR 100 (air entraining agent) to concrete is recommended where it is required to withstand freezing and thawing cycles.
Packaging
RHEOBUILD 850 is available in bulk or in 210 litre drums.
Typical properties
Colour: |
Brown liquid |
Specific gravity: |
1.197 at 25°C |
Chloride content: |
Nil to BS 5075 Part 1 |
Freezing point: |
0°C |
Flashpoint |
N/A |
Standards
ASTM C-494 Type B, D and G
Dosage
Optimum dosage of RHEOBUILD 850 should be determined in trial mixes. As a guide the following dosages are recommended as a starting point for any trial. In normal concrete a dosage of between 0.8% and 2%. In high performance micro silica concrete a dosage of between 1.5 and 3%. Dependant upon mix requirement, it is possible to use a higher dosage of RHEOBUILD 850 without causing any adverse effects upon the concrete. Please consult BASF Middle East Technical staff for further information.
Dispensing
RHEOBUILD 850 is a ready-to-use liquid which is dispensed into the concrete together with the mixing water. The plasticising effect and water reduction are higher if the admixture is added to the concrete after 50 to 70% of the mixing water has been added. The addition of RHEOBUILD 850 to dry aggregate or cement is not recommended. Automatic dispensers are available.
Workability
RHEOBUILD 850 ensures that rheoplastic concrete remains workable in excess 3 hours at +20°C.
Workability loss is dependent on temperature, and on the type of cement, the nature of aggregates, the method of transport and initial workability. It is strongly recommended that concrete should be properly cured particularly in hot and dry climates.
Storage
RHEOBUILD 850 must be stored where temperatures do not drop below +5°C. If product has frozen thaw and agitate until completely reconstituted. Store under cover, out of direct sunlight and protect from extremes of temperature.
Failure to comply with the recommended storage conditions may result in premature deterioration of the product or packaging. For specific storage advice consult BASF's Technical Services Department.
Safety precautions
RHEOBUILD 850 is not a fire or health hazard. Spillages should be washed down immediately with cold water. For further information refer to the 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.