Batimix Anti-Corrosion M-840

Description

BATIMIX Anti-Corrosion M-840 is a calcium nitrite based liquid admixture used to patch and repair mortars to inhibit 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 cement-based mortar leads to the formation of a passivating layer protecting steel rebars from corrosion. However, such a passive ferric oxide layer can be damaged by the presence of chlorides combined with moisture and oxygen. This would result in cracking, spalling, and failure of structural elements.

BATIMIX Anti-Corrosion M-840 chemically oxidizes steel inhibiting 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.

Applications using BATIMIX Anti-Corrosion M-840 include all types of mortars and grouts used for repair, patching, and pointing applications of structures containing steel embedment.

Features

Mortars prepared with BATIMIX Anti-Corrosion M-840 are 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 steel corrosion and rust formation
• Chemically inhibits the corrosion process
• Longer mortar service life and better surface quality

Properties

• Appearance: pale yellow liquid
• Specific gravity: around 1.21 at 23 ºC
• Chloride content: nil
• Alkali content: typically less than 0.5% as Na₂O
• Air entrainment: typically less than 0.5% at normal dosages
• Solid content: minimum 30%
• Freezing point: -10 ºC

Health and Safety

BATIMIX Anti-Corrosion M-840 is not a hazardous material. 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 M-840 is developed to comply with the requirements of BS 8443:2005.

Dosage Rates

When designing mortar mixes with BATIMIX Anti-Corrosion M-840, it is necessary to reduce the free water content to maintain constant workability. Its recommended addition rate may range from 1% to 5% of cement weight, depending on the expected chloride concentration attack. 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 conditions that will be experienced in use.

Effect of Overdosing

An overdose of BATIMIX Anti-Corrosion M-840 will generally produce a significant loss in workability and slightly increased early strength as compared to that normally obtained.

Compatibility

BATIMIX Anti-Corrosion M-840 is compatible with all types of Portland cement, replacement materials such as silica fume, and other Holderchem admixtures incorporated in the same mortar. During batching, all admixtures should be added separately to the mortar mix. The performance of various admixtures on the fresh and hardened mortar properties should be assessed using trial tests.

Dispensing

BATIMIX Anti-Corrosion M-840 should not be directly added 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, technical advisory services pertaining to mix design, admixture selection, and materials evaluation.

Storage

BATIMIX Anti-Corrosion M-840 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