Henkel Polybond SBR
SBR based bonding agent and admixture
Polybond SBR is a Styrene butadiene Rubber copolymer based product which is used in mortar and concrete as an admixture and bonding agent to increase its water resistance and durability.
- Enhances the flexural and tensile strength of the mortar and render
- Provides good resistance to water and moisture vapour transmission
- Improves the chemical and abrasion resistant properties of the mortar
- Can be applied in thin screed without cracking
- Reduces the water/cement ratio
- Easy to use
- Compatible with all types of cements
- Reduces shrinkage
- Excellent adhesion to most building materials
- Good resistance to salt permeation
- Prolonged corrosion protection
- Similar thermal expansion and modulus properties like concrete
- Can be used in potable water applications
Surface to which Polybond SBR mixes are to be applied shall be clean, sound and free of all loose particles. Remove all laitance, oil & grease, mould oil, curing compound from surface. Ensure that the exposed reinforcing steel is clean and free from scale and rust. When repairing damaged concrete, ensure that the concrete has been cut back to thoroughly sound material.
Saturate absorbent surfaces with water completely till it reaches a saturate surface dry condition. however, ensure that the surface is free of standing water. Prepare a bonding slurry by mixing 2 parts o.p. cement to 1 part of Polybond SBR (by volume). Using a stiff brush, work the bonding slurry well into the damp surface, ensuring that no pinholes are visible. Do not apply bonding slurry at a thickness in excess of 2mm. If a second coat is necessary, it must be applied at right angles to the first to ensure complete coverage. (approximately 25L of Polybond SBR mixed with 50 kg of o.p cement will give a creamy slurry which will cover 15-40m2 depending on the surface texture and thickness applied).
Polybond SBR minimum dosage of 10L per 50 kg of cement is recommended to be used. For more demanding situations 15L per 50 kg of cement is recommended. Mixing should be carried out in an efficient concrete mixer – where available a pan type mixer is recommended. Pour the required quantity of sand and cement and premix for approximately one minute. Pour the required quantity of Polybond SBR and mix for two minutes. Add the water slowly until the required consistency is achieved. Avoid adding excessive water which will result in segregation and bleeding.
Apply the bonding slurry to the prepared surface and then render immediately with Polybond SBR modified mortar. Apply in coats to a maximum thickness of 5mm per coat. Several coats can be applied at intervals of 20 –30 minutes. Thicker coating can be applied when suitable form work is used. Finish the surface using wooden float or steel trowel.
As soon as the Polybond SBR modified mortar and screed achieves its final set, adequate curing shall be carried out. Water sprinkling, ponding or the use of a non-degradable type of curing compound may be used.