Microsilica SF

Microsilica SF, more commonly known as silica fume, is a by-product of producing silicon metal or ferrosilicon alloys in electric furnaces. The fumes emitted from furnace operation are collected and sold as silica fume. It's used to provide an increase in durability in concrete.


Microsilica SF consists primarily of amorphous (non-crystalline) silicon dioxide (SiO2). The individual particles are extremely small, approximately 1/100th the size of an average cement particle. Because of its fine particles, large surface area, and the high SiO2 content, Microsilica SF is a very reactive pozzolan when used in concrete. The quality of silica fume is specified by ASTM C 1240.

Microsilica SF meets the requirements of AS/NZS 3582.3.  One of the most beneficial uses for silica fume is in concrete due to its chemical and physical properties. Concrete containing silica fume can have very high strength and can be very durable.


Microsilica SF’s chemical and physical properties make it highly beneficial to use in concrete. It’s the product of choice for increasing strength and durability.

Benefits of using using Microsilica SF in concrete mixes include:

Hardened concrete

  • Increased tensile strength
  • Increased long-term compressive strength development
  • Reduced efflorescence

Durability and other properties

  • Increased sulphate resistance
  • Increased chloride resistance
  • Reduced water permeability
  • Increased Abrasion Resistance


Microsilica SF is available in multi-walled paper sacks and in bulk.

microsilica grey
microsilica grey

Typical Properties

Typical Properties

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