Corrosion inhibitor
PAMIX CNI
Corrosion-inhibiting chemical admixture for reinforced concrete
Translated from the Spanish data sheet. Standard designations, ASTM type numbers, figures and units are reproduced unchanged; in case of doubt the Spanish PDF governs.
Description
PAMIX CNI is an admixture formulated with a calcium nitrite base to inhibit the corrosion of steel in reinforced concrete. It complies with specification ASTM C494/C494M for type C accelerating admixtures.
Recommended applications
- Reinforced concrete structures exposed to chloride ions during their service life.
- Parking structures.
- Bridges and infrastructure works.
- Concrete batched with materials that contribute chlorides to the mix.
- Concrete in severely corrosive environments.
Advantages
- Effective protection against chloride-induced corrosion in concrete.
- Longer service life for reinforced concrete structures.
- It does not initiate or promote corrosion of the embedded reinforcing steel.
- Non-corrosive. Contains no chlorides.
- Compatible with the other admixtures in the PAMIX line.
Dosage
Reference dosage 5 to 30 L/m³ of concrete
The recommended dosage range for PAMIX CNI is 5 to 30 L/m³ of concrete, depending on the severity of the corrosive environment and the anticipated chloride loading for the structure. Consult your PAMIX INTERNATIONAL, S.A. representative.
The dosage can be calculated from the anticipated chloride loading and the applicable chloride/nitrite ratio:
Dosage (L/m³) = 3.69 × Anticipated chloride loading (kg/m³) ÷ Chloride/nitrite ratio Dosage (gal/yd³) = 0.441 × Anticipated chloride loading (lb/yd³) ÷ Chloride/nitrite ratio
Compatibility
PAMIX CNI can be used in combination with any of the admixtures in the PAMIX line. If used together with other admixtures, add each one to the mix separately.
Performance characteristics
In the alkaline environment of concrete, a natural passive ferric oxide layer forms on the surface of the embedded reinforcing steel, protecting it from corrosion. This passive oxide layer can break down in the presence of chlorides and moisture, resulting in corrosion of the steel. PAMIX CNI acts by inhibiting this mechanism.
PAMIX CNI will not initiate or promote corrosion of reinforcing steel embedded in concrete, in prestressed concrete, or in concrete placed over galvanised steel floor and roof systems. No calcium chloride or chloride-containing ingredients are used in its manufacture.
Setting time
The setting of the concrete can be accelerated by the use of PAMIX CNI. If required, a hydration control or retarding admixture from the PAMIX line can be added to the mix to counteract the accelerating effect. Consult your technical advisor at PAMIX INTERNATIONAL, S.A. for the appropriate set balance.
Chloride protection limits
PAMIX CNI can be used to counteract the potentially corrosive effects of chloride-bearing ingredients used in concrete, and in applications where the initial chloride ion content of the concrete may exceed code requirements or other specified limits.
The limits for applications involving the use of chloride-bearing materials are based on a critical chloride/nitrite ratio of 0.90, in accordance with the recommendations of the United States Federal Highway Administration (FHWA – Federal Highway Administration). These limits may also be used in very severely corrosive environments for reinforced protection, if desired.
The chloride protection limits for all other applications, such as parking structures and bridges, are based on critical chloride/nitrite ratios in the range of 1.20 to 1.50.
Concrete structures with reinforcing steel that will be exposed to chloride ions during their service life must be designed in accordance with the specifications of the American Concrete Institute ACI 318, ACI 357, CSA, AASHTO or other applicable codes.
| PAMIX CNI dosage L/m³ (gal/yd³) | With chloride-bearing materials kg/m³ (lb/yd³) | Other applications kg/m³ (lb/yd³) |
|---|---|---|
| 5.0 (1.0) | 1.2 (2.1) | — |
| 10.0 (2.0) | 2.4 (4.1) | 3.6 (6.0) |
| 15.0 (3.0) | 3.6 (6.1) | 5.9 (9.9) |
| 20.0 (4.0) | 4.8 (8.1) | 7.7 (13.0) |
| 25.0 (5.0) | 6.0 (10.1) | 8.9 (15.0) |
| 30.0 (6.0) | 7.2 (12.1) | 9.5 (16.0) |
Safety
Consult the Safety Data Sheet (HDS/MSDS) for this product before use. For further information about this product, or for its use in developing concrete mixes with special performance characteristics, consult your technical advisor at PAMIX INTERNATIONAL, S.A.
Storage
A storage temperature of -12 to 38 °C (10 to 100 °F) is recommended for PAMIX CNI. If the product freezes, it can be fully reconstituted by thawing and agitating it mechanically. Do not use pressurised air to agitate.
The admixture should be kept closed and sealed at all times in its original containers, in a roofed store protected from the weather.
Packaging
PAMIX CNI is supplied in bulk, in 208 L (55 gal) drums and in 1,040 L (275 gal) tanks.
Shelf life
6 months minimum in the original unopened container. Depending on storage conditions the shelf life may be longer.
Standards and compliance
- ASTM C494/C494M, aditivo tipo C.
Data sheet version 3. The PDF is the reference document. Warranty →
Documentation
Support
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