In concrete, sodium metabisulfite serves the following potential functions:

Dechlorination: Sodium metabisulfite can be used to remove excess chlorine from water used in the concrete mix. Chlorine can sometimes be present in water used for concrete production, and its presence can potentially affect the setting time and strength development of the concrete. Sodium metabisulfite reacts with chlorine to form harmless chloride ions and sulfur dioxide.

Oxygen Scavenging: Sodium metabisulfite can act as an oxygen scavenger, reacting with dissolved oxygen in water used in the concrete mix. This can be particularly relevant in situations where the presence of oxygen may lead to oxidation reactions that could potentially affect the performance or appearance of the concrete.

Reduction of Chromium: In certain specialized applications, sodium metabisulfite might be used to reduce hexavalent chromium (Cr(VI)) in cementitious materials. Hexavalent chromium is a toxic substance, and reducing it to trivalent chromium (Cr(III)) can mitigate its environmental and health risks.

It’s important to note that the use of sodium metabisulfite in concrete would likely be limited and specific to certain circumstances, such as addressing water quality issues or controlling chemical reactions. As with any additive, its use should be carefully considered and tested to ensure that it does not adversely affect the properties or performance of the concrete. Additionally, adherence to safety guidelines and regulations is essential when handling and using chemicals in concrete production.

What Is The Function Of Sodium Metabisulfite In Concrete