KingRep Primer CM3®
Three-component, solvent-free, moisture-tolerant, epoxy-modified cementitious bonding agent and anti-corrosion coating.
SpecWorld has the Spec Pack, CSI specification and drawings for registered specifiers.
- Splitting tensile strength ASTM C496
- > 4.5 MPa @ 28 days
- Pot life
- 60 min @ 25°C
- Mixed density
- 1.9 ± 0.05 g/cm³
Overview
KingRep Primer CM3 is a three-component, solvent-free, moisture-tolerant, epoxy-modified cementitious product formulated as a bonding agent and an anti-corrosion coating.
It protects steel reinforcement with a highly alkaline passivating layer and with migrating corrosion inhibitor technology, which limits further corrosion of the surrounding reinforcement.
Where to use
- Corrosion protection of steel reinforcement in concrete repair systems.
- Bonding slurry between KingKrete cementitious repair systems and the concrete substrate.
Why use it
- Excellent adhesion to concrete and steel.
- Effective barrier against water and chlorides (not a vapour barrier).
- Long open time.
- Bonding agent and corrosion protection in one product.
- Can be used on exterior surfaces.
- Contains corrosion inhibitors.
- Excellent bonding bridge for cement-based or epoxy-based repair mortars.
- High strength.
- Unaffected by moisture once cured.
- Applied by spray, brush or roller.
- Non-flammable and solvent-free.
Technical properties
| Colour | Concrete grey |
|---|---|
| Mixed density | 1.9 ± 0.05 g/cm³ |
| Pot life | 60 min @ 25°C |
| Application temperature | 5 - 45°C |
| Compressive strength (ASTM C109) | ≥ 55 MPa @ 7 days ≥ 65 MPa @ 28 days |
| Flexural strength (ASTM C348) | ≥ 5 MPa @ 7 days ≥ 8 MPa @ 28 days |
| Splitting tensile strength (ASTM C496) | > 4.5 MPa @ 28 days |
| Bond of steel to concrete, pull-out | Bar coated with KingRep Primer CM3: 4.3 MPa Epoxy-coated bar: 3.5 MPa Plain bar: 3.96 MPa |
| Water permeability (DIN 1048, 5 bar) | 0% |
| Water permeability coefficient at 10 bar | 2.72 × 10⁻¹⁵ m/s Control: 2.23 × 10⁻¹⁰ m/s |
| Carbon dioxide diffusion resistance coefficient, μCO₂ | 14,000 |
Standards and approvals
KingRep Primer CM3 conforms to the requirements of EN 1504-7 for active and barrier coatings that protect existing uncoated steel reinforcement and embedded steel in concrete structures under repair.
How to use
Method of use
Substrate preparation
Clean and prepare cementitious substrates by blast cleaning or equivalent mechanical means to an open-textured surface free from laitance and contaminants. The substrate must be saturated surface dry (SSD), with no standing water.
Clean steel thoroughly to white metal by blast cleaning (SSPC-SP 5 / NACE No. 1).
Mixing
Shake Components A and B, then empty the entire contents of both into a clean, dry mixing pail. Mix for 30 seconds with a paddle on a low-speed drill (400 - 600 rpm). Slowly add the entire contents of Component C while mixing continuously for 3 minutes, until the blend is uniform and free of lumps. Mix only as much as can be applied within 60 minutes.
As a bonding agent
Apply with a stiff bristle brush or broom, or spray with a hopper gun or similar equipment. Work the slurry well into the substrate so that every surface irregularity is covered. Apply the freshly mixed repair mortar or concrete wet on wet, or within the maximum open time. The minimum thickness as a bonding agent is 0.5 mm.
As corrosion protection for reinforcing steel
Apply with a stiff bristle brush, about 0.5 mm per coat, taking particular care to coat the underside of fully exposed bars. Allow the first coat to dry for 2 - 3 hours at 23°C, then apply a second coat at the same rate. Allow the second coat to dry before the repair mortar or concrete is placed. The minimum total thickness to protect reinforcement is 1 mm (two coats of 0.5 mm).
Cleaning
Clean all tools with fresh water immediately after use. Hardened material can only be removed mechanically.
Coverage, packaging and storage
Coverage
Bonding agent on a smooth surface: 2.0 m² per litre at 0.5 mm dry film thickness.
Reinforcement protection on an irregular surface: 1.0 m² per litre per coat at 0.5 mm dry film thickness. Apply two coats for a total of 1.0 mm.
Packaging
KingRep Primer CM3 is available in 20 kg kits: Part A 2.9 kg, Part B 1.1 kg and Part C 16 kg.
Storage
Shelf life is 1 year when stored under cover, out of direct sunlight and protected 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 KingKrete's Technical Services Department.
Health and safety
As with all chemical products, care should be taken during use and storage to avoid contact with eyes, mouth, skin and foodstuffs. Treat splashes to eyes and skin immediately. If accidentally ingested, seek medical attention. Reseal containers after use. Use in well ventilated areas and avoid inhalation.