SILICA FUME

Improve Strength, Durability and Rheology

Silica Fume

Silica Fume is a byproduct of producing silicon metal or ferrosilicon alloys. One of the most beneficial uses for Silica Fume is in concrete. Because of its chemical and physical properties, it is a very reactive pozzolan. Concrete containing Silica Fume can have very high strength and can be very durable.

What is Silica Fume?

Silica fume is a filter powder generated from the reduction of high purity quartz – ferrosilicon metals or silicon metals. Silica fume consists primarily of very fine smooth spherical silicon oxide particles with an extremely high surface area. Silica fume’s chemical and physical typical composition is shown in Fig.1 in comparison with OPC cement, fly ash and slag.

Fig.1 Chemical Composition

 UnitPortland CementSlagFlyashSilica Fume
CaO%60 - 6732 - 481 - 50.1 - 0.6
SiO2%17 - 2528 - 4040 - 5586 - 95
Al2O3%2 - 810 - 2220 - 300.2 - 2.2
Fe2O3%0 - 63 - 55 - 100.2 - 2.2
MgO%0.1 - 4.02 - 161 - 40.3 - 3.5
SO3%1 - 42 - 40.4 - 2.00.4 - 1.5
Na2O%0.1 - 1.00.2 - 1.20.1 - 2.00.2 - 1.8
K2O%--1 - 6

Silica Fume Application In Concrete

Low Heat Concrete

(LHC)
Infrastructure, Buildings, Industrial

Low Heat Concrete

By replacing cement with silica fume and observing the efficiency factor of silica fume, a lower maximum temperature rise, and temperature differential will take place for concrete with the same strength. It is also the most effective way of achieving low heat without sacrificing early age strength.

Waterproof Concrete

(WPC)
Infrastructure, Buildings, Industrial

Waterproof Concrete

Because of its low permeability, silica fume can be used as an integral waterproofer for below ground structures where some dampness is acceptable, e.g. car-parks.

Corrosion Resistance

(CRC)
Infrastructure, Buildings, Industrial

Corrosion Resistance

Silica fume concrete is suitable for structures exposed to saltwater, de-icing salts, i.e. harbour structures, ports, bridges, docks, onshore constructions situated in areas with chlorides in the ground water, soil and in the air.

High Strength Concrete​

(HSC)
Infrastructure, Buildings, Industrial

High Strength Concrete​

SilicaFume provide large economic benefits to developers e.g. reduced column and wall thickness in tall buildings and improved construction schedule. It is also easier to pump silica fume concrete up the high-rise buildings during construction.

Self-Compacting Concrete

(SCC)
Infrastructure, Buildings, Industrial

Self-Compacting Concrete

Silica fume concrete is cohesive due to its very high surface area and hence prevent segregation and bleeding. This becomes very useful in self-compacting concrete which is very high flow and prone to segregation.

Sulphate Resistance​

(SRC)
Infrastructure, Buildings, Industrial

Sulphate Resistance​

Silica Fume concrete has a low penetrability and high chemical resistance that provides a higher degree of protection against sulphates than low C3A sulphate resisting cements or other cementitious binder systems

Chemical Resistance

(ChemRC)
Infrastructure, Industrial

Chemical Resistance

Silica fume concrete is widely used in industrial structures exposed to an array of aggressive chemicals. Silica fume concrete is therefore invaluable in the industrial and agricultural sectors.

Abrasion Resistance

(ARC)
Infrastructure, Industrial

Abrasion Resistance

Silica fume concrete has very high abrasion resistance. In floor and pavement construction it's use saves money and time and improves operational efficiencies for the facility operator. It also improves the hydraulic abrasion-erosion resistance of concrete thus making it suitable for use in dam spillways.

Shotcrete​

(SC)
Infrastructure

Shotcrete​

Silica fume is used in shotcrete whether produced by wet or dry process to reduce the rebound, to increase application thickness per pass, improve resistance to wash out in marine construction or wet areas and to improve the properties of hardened shotcrete. With fibres it can eliminate mesh and reduce cracking.

How Does Silica Fume Improve Concrete?

Pozzolanic Reaction

When water is added to OPC, hydration occurs forming two products, as shown below:

OPC + H2O -> CSH (Calcium silicate hydrate) + Ca(OH)2

In the presence of silica fume, the silicon dioxide from the silica fume will react with the calcium hydroxide to produce more aggregate binding CSH as follows:


Ca(OH)2  + SiO2 + H20   ->  CSH 

The reaction converts the calcium hydroxide into calcium silicate hydrate (which is the binder in concrete) as shown in Fig. 2. The weaker calcium hydroxide does not contribute to strength. When combined with carbon dioxide, it forms a soluble salt which will leach through the concrete causing efflorescence, a familiar architectural problem. Concrete is also more vulnerable to sulphate attack, chemical attack and adverse alkali-aggregate reactions when high amounts of calcium hydroxide is present in

Microfiller Effect

Silica Fume is an extremely fine material, with an average diameter 100x finer than cement (Fig 3). At a typical dosage of 8% by weight of cement, approximately 100,000 particles for each grain of cement will fill the water spaces in fresh concrete (Fig 4). This eliminates bleed and the weak transition zone between aggregate and paste found in normal concrete. This microfiller effect will greatly reduce permeability and improve the paste-to-aggregate bond of silica fume concrete compared to conventional concrete.

The silica reacts rapidly (Fig 5) providing high early age strengths and durability. The efficiency of silica fume is 3-5 times that of OPC and consequently vastly improved concrete performance can be obtained.

Project Profile

Changi Water Reclamation Project (CWRP) Singapore

We are proud to be the Silica Fume Supplier to the Concrete Manufacturer for this project required to supply High Durability Concrete to meet the durability requirement.

Changi Water Reclaimation Project (CWRP) which was officially opened in August 2006 is a milestone event in the development of sanitation system in Singapore using the latest technology. The implementation of CWRP transforms the management of waste water in Singapore and provides high sanitation standards in Singapore for generations to come. Today in Singapore we consume about 300 million gallons of clean water a day. Changi Water Reclamation Plant (CWRP) provides the solution to the needs to increase water capacity with the state of art, compact and covered facilities. 

Get In touch

We understand that choosing the correct solution and type of product is essential for the success of any project. Scancem Materials has a technical support team with many years of concrete industry experience and successful project applications and are ready to help you find the right solution for your application.

Singapore

+65 6748 9808

8 Ubi Road 2, #06-04 Zervex, Singapore 408538

malaysia

+603-91712110

A-4-9 Plaza Dwi Tasik, Jln Sri Permaisuri, Bandar Sri Permaisuri, 56000 Kuala Lumpur