Batimix Anti-Corrosion 620

Description

BATIMIX Anti-Corrosion 620 is a calcium nitrite liquid admixture that inhibits corrosion of steel reinforcements embedded in concrete. It is blended with set-retarding chemicals to offset any acceleration that may occur due to calcium nitrite.

Main Purpose

In normal circumstances, the high alkalinity of concrete leads to the formation of a passivating layer that protects steel rebars from corrosion. However, such a passive ferric oxide layer may be damaged by the presence of chlorides, which damage when combined with moisture and oxygen results in cracking, spalling, and failure of concrete structural elements.

BATIMIX Anti-Corrosion 620 is designed to chemically oxidize the steel to inhibit corrosion and rust formation. When used at recommended dosage rates, it prevents ferrous chloride complex formation by reacting with defective ferrous oxide ions prior to chloride attack, reforming the passivating layer. Nitrite ions surround the defective ferrous oxide ions and convert them to more stable ferric ion species less susceptible to corrosion.

BATIMIX Anti-Corrosion 620 is applied to newcast and repaired structures that are potentially vulnerable to corrosion. These include steel-reinforced, precast, pre-stressed, and post-tensioned concrete.

Features

Concrete prepared with BATIMIX Anti-Corrosion 620 is characterized by the following:

In the plastic state:

• Normal setting rates under moderate temperatures
• No detrimental effect on workability or strength

In the hardened state:

• Reduced potential for corrosion and rust formation
• Chemically inhibits the corrosion process
• Longer concrete service life and better surface quality

Properties

• Appearance: light brown liquid
• Specific gravity: 1.21 ± 0.02 at 23 ºC
• Solid content: minimum 30%
• Chloride content: nil
• Alkali content: typically less than 0.5% as Na₂O
• Air entrainment: typically less than 0.5%

Health and Safety

BATIMIX Anti-Corrosion 620 is not considered a hazardous product. However, it should not be swallowed or allowed to come into contact with skin and eyes. Suitable gloves and goggles should be worn. For additional information, kindly refer to the product’s Material Safety Data Sheet.

Compliance with Standards

BATIMIX Anti-Corrosion 620 complies with the requirements of BS 8443:2005.

Dosage Rates

BATIMIX Anti-Corrosion 620 is generally added at a dosage rate varying from 1% to 6% of the cement weight, depending on the expected chloride concentration attack and structure exposure to aggressive environmental ions. For indication purposes, users may refer to the below equation or table to determine the needed dosage rate.

Dosage rate (kg/m³) = 2.04 Exp (0.236 × expected chloride content in kg/m³)

| BATIMIX Anti-Corrosion 620 (kg/m³) | Chloride content (Kg/m³) | |------------------------------------|--------------------------| | 4 | 3.5 | | 6.5 | 4.75 | | 8.5 | 5.8 | | 11 | 6.5 | | 12.5 | 7.6 | | 15 | 8.5 | | 19.5 | 9.7 |

The effect of the intended dosage on the fresh and hardened properties such as workability and strength is best determined by trials using the actual mix composition and site materials under field conditions.

Important note: the free water content should be reduced when designing concrete mixes with BATIMIX Anti-Corrosion 620 to maintain similar W/C, and therefore similar compressive strength.

Effect of Overdosing

An overdose of BATIMIX Anti-Corrosion 620 will generally produce a significant loss in workability as compared to that normally obtained. Provided that adequate curing is implemented, the development of compressive strength will not be affected.

Compatibility

BATIMIX Anti-Corrosion 620 is compatible with all other Batimix admixtures incorporated in the same concrete. During batching, all admixtures should be added separately to the concrete mix. The performance of various admixtures on the fresh and hardened concrete properties should be assessed using trial tests.

Concrete mixtures based on Portland cement with or without replacement materials such as silica fume, fly ash, and blast furnace slag are compatible with BATIMIX Anti-Corrosion 620.

Dispensing

Automatic dispensing systems should preferably be used to introduce the correct quantity of BATIMIX Anti-Corrosion 620 in the concrete mixer. This admixture should not be directly introduced on the dry cement. It should rather be added at end of mixing, i.e. after incorporating all of the mixing water and other chemical admixtures.

Technical Support

Holderchem provides, upon request, complete technical support and on-site assistance to enable correct and effective use of its products.

Storage

BATIMIX Anti-Corrosion 620 has a minimum shelf life of 12 months if kept unopened and stored at temperatures ranging from 2 to 50 ºC.

Packages

• 1 t IBC
• 200 kg metallic drum
• 20 kg metallic pail
• 4 kg metallic pail