Chembond

Description

Chembond is a synthetic latex which, when added to mortar and concrete mixes, enhances their basic properties. It gives the cured compound exceptional adhesion to brick, concrete, ceramic tiles and enhances adhesion to other common building materials such as timber, most metals, expanded polystyrene foam and rigid polyurethane foam.

Uses

Chemind Chembond produces premium quality, high performance polymer modified cement (PMC) mixes. It is used for all external or high performance applications to concrete, brick or block, including:

Adhesive binder for render systems

Bedding to tiles and pavers

Repair of concrete and masonry

Thin topping/levelling screeds

High strength grout or bedding mixes

Sealer for concrete, FC and CFC sheet

Bonding agent for Krystol slurry

Waterproof grouts and coatings

Bagging of block and brick walls

Features

No toxic or hazardous ingredients

Water cleanup

Resists spalling - moves with substrate

Boosts tensile and compressive strength

Increases flexural and adhesive strength

Resists acids, alkalis and fats

Excellent exterior durability

Totally waterproof

Multi-purpose and easy to use

Single pack

Economical with high performance

Systems for Total Project Specification

Typical Properties

Property	No Chembond	Chembond @ 25% wt Cement
Adhesion to concrete (N/mm²)	0.07	2.1
Adhesion to dry steel (N/mm²)	0.0	2.0
Tensile strength (N/mm²)	2.0	4.0
Compressive strength (N/mm²)	56.0	50.0
Flexural strength (N/mm²)	7.1	13.2
Flexural strength after 1 year @ 70°C (N/mm²)	5.2	14.3
Adhesion to concrete after 6 months @ 70°C (N/mm²)	0.0	1.9
Shrinkage during drying (% shrinkage)	0.07	0.01
Water vapour permeability (g/m²/24 hrs)	46.9	4.0
Water penetration (kg/m²/24 hours)	100	30

Preparation

All surfaces must be sound, smooth, dry and free from dust, loose matter, oil, grease or other contaminants.

Bony concrete should be removed.

All exposed concrete and any exposed steel should be coated with a slurry coat of Chembond:Water:Cement:Sand (1:1:1:1).

Porous or very smooth surfaces should also be primed with a slurry coat.

Fine sand may be deleted depending on surface finish required.

Dampen surface prior to applying slurry.

NOTE

Application to porous substrates at elevated temperatures or in windy conditions may result in trowelling difficulties, poor surface adhesion and fine shrinkage cracking.

Application

Renders

Do not exceed 7 mm for each coat. Thicker coats may cause sagging or separation from wet primer coat. Scratch surface of each coat and leave for at least 6 hours before applying further coats. Trowel final coat to required finish.

Floor Toppings

Toppings based on Chembond can be laid to any thickness (12 mm min.) depending on the sieve grading of the sand. Feather edging is permissible for non-critical areas but use of 24 hr damp curing is particularly important.

Trowelling

Use semi-dry mix. Mixed consistency must readily allow total compaction by methods used. Chembond mortar should be placed over the still wet priming coat. It is then levelled, compacted and floated smooth. Finish as required. Thick topping slabs (50 mm+) do not require Chembond additive but should be placed directly onto a wet Chembond priming coat.

Mixing Ratio

General – Dilute Chembond with 4 to 5 parts water and add to dry ingredients.

Waterproof Render – Dilute Chembond with 2 parts of water and add to dry ingredients.

Krystol – Dilute Chembond with 5 parts of water and add this to Krystol powder to obtain required consistency.

Mix Design Data

Chembond diluted with 5 parts of water required for 1m³

Standard Concrete – 160 - 170 litres

Mortar/Screed – 200 litres

Concrete Repair Mortar

-1 pbw cement : 3 pbw sand

-add Chembond/water 1 : 1 mix, to achieve required consistency.

Topping < 10mm thick

-1 pbw cement : 2 pbw sand

-add Chembond/water 1 : 1 mix, to achieve required consistency.

Topping to 20mm thick

-1 pbw cement : 5 pbw sharp sand

-add Chembond/water 1 : 5 mix, to achieve required consistency.

Bagging render/texture

-1 pbw cement: 4 parts fine sand

-add Chembond/water 1 : 2 mix, to required slurry consistency.

Packaging

Chembond is packed in 20 litre pails and 200 litre drums.

Shelf Life

Unopened or resealed pails of Chembond will have a shelf life of 2 years, when stored in a dry, cool place. Protect from frost.

Clean-up

Clean with water before final cure occurs. Chemind GP Solvent may assist with the removal of partially cured product. Exercise care when using solvents. Please review all MSDS before use.