Sodium formate or sodium salt of formic acid is a chemical compound that is a product of the processing of the tetrahydric alcohol pentaerythritol. As a by-product, it contains the following components:
• sodium formate;
• pentaerythritol;
• derivatives of pentaerythritol
According to its physical and chemical properties, sodium formate is a sodium salt of formic acid, a powdery substance is often white (but colors of green and gray blotches are acceptable), without the spread of foreign impurities, with a humidity of around 3%.
Chemical formula: HCO2Na.
Basic properties:
• fast solubility in water;
• low solubility in alcohol;
• insolubility in ethers;
• non-flammable;
• non-toxic;
• does not harm the environment.
Technical sodium formate is used in many areas, such as construction, raw materials production in the chemical and leather industries, etc.
The use of sodium formate in construction is due to its antifreeze properties. To add resistance to negative temperatures, the sodium salt of formic acid is added to concrete and reinforced concrete structures during the construction of monolithic and precast-monolithic structures. When using sodium formate, work with monolithic structures is permissible when the air temperature drops to -5°C.
The content of sodium formate in concrete compositions is regulated by the level of temperature decrease:
• At a temperature of -5°C sodium formate in the composition is up to 2%.
• When the temperature drops to -10°C, the content of sodium formate can be up to 3%.
• The content of sodium formate in the formulations when working at -15°C reaches up to 4%.
Nuances when using with concrete compositions:
• Sodium formate is dissolved in warm water and then added to the concrete mix.
• Sodium formate can be used together with superplasticizers, including C-3.
• Not used in stressed, water, gas structures, buildings of electrified transport.
• It is forbidden to use under dynamic loads on concrete structures.
• Not used if the expected humidity in buildings is more than 60%, and waterproofing is not used.
The main properties of the use of sodium formate in construction are due to the following characteristics of the chemical compound:
• Sodium formate controls the curing speed, ie. speeds up or slows down the curing process of concrete.
• Sodium salt of formic acid increases concrete mobility.
• Sodium formate imparts antifreeze, air-entraining, protective properties to concrete compositions and reinforcing components.