SILICA FUMES CONCRETE

Silica Fume Concrete

Silica fume concrete is composed of cement, silica fume, fine aggregate, coarse aggregate and water.

Silica fume is a byproduct of producing silicon metal or ferrosilicon alloys.Because of its chemical and physical properties, it is a very reactive pozzolan. Silica fume concrete can have very high strength and can be very durable. The durability of this type of concrete is superior to conventional concrete.In silica fumes concrete segregation and bleeding is low and the mixture is adhesive compared to traditional concrete.

Because of its extreme fineness and high silica content, silica fume is very effective pozzolanic material.The applications of silica fume concrete in construction are seen in high-rise building, parking structure, dams, nuclear waste storage facility and shotcrete rehabilitation.

Chemical Composition Of  Silica Fume Material

• It contains more than 90% of silicon dioxide.
• Other constituents are carbon, sulfur, iron, calcium, magnesium, sodium, potassium and oxides of aluminum.

Physical Properties Of  Silica Fume Material

• The diameter of the silica fume particle range from 0.1 micron to 0.2 micron.
• The surface area is about 30000 m2/kg.
• Density varies from 150 to 700 kg/m3.
• The shape of particle is spherical.

Properties Of Fresh Silica Fume Concrete

• Low workability.
• Low slump value.
• High plastic shrinkage.
• The mixture is cohesive.
• Bleeding and segregation is low.
• It requires higher water content.

Properties Of Hardened Silica Fume Concrete

• The modulus of elasticity is higher than that of ordinary concrete.
• Creep of silica fume concrete is lesser than conventional concrete.
• The compressive strength of silica fume concrete is higher than ordinary concrete (6000 - 8000 psi).

Advantages Of Silica Fume Concrete

• High durability.
• High bond strength.
• High flexural strength.
• High modulus of elasticity.
• High compressive strength.
• It reduces segregation and bleeding.
• High electrical resistivity and low permeability.
• It is suitable for mass concreting since it prevents thermally induced cracking.

Disadvantages Of  Silica Fume Concrete

• Expensive.
• Availability issue.

Applications Of  Silica Fume Concrete

• Dam structure.
• Parking structure.
• High rise building.
• Shotcrete rehabilitation .
• Nuclear waste storage facility.

DAM  STRUCTURE

PARKING  STRUCTURE

HIGH  RISE  BUILDING