Methods for Production of High-Strength Concrete

April 21, 2020

High strength concrete is produced by various methods such as re-vibration, the use of admixtures, high-speed slurry mixing, prevention of cracks, Sulphur impregnation or Sulphur filling, use of cementitious aggregates, and seeding.

Let’s discuss this methods in depth.

Use of Admixture

This is the broad methods to produce high strength concrete by reducing water content hence increase the strength in comparison to plasticizer and superplasticizer. Pozzolanic materials like fly ash and silica fume are mineral admixtures that are usually added to the concrete mix. The pozzolanic materials react with Portland cement hydration product and generate extra C-S-H, extra strength added to concrete. The C-S-H gel is responsible for the strength of concrete.

Re-Vibration

Water mixing in concrete can bleed, gather at certain places and cause shrinkage that will decrease the strength of concrete. So in this case a controlled re-vibration of concrete would decrease harmful influences of this factors and increase the strength.

High-speed slurry mixing

In this first cement and water mixture is prepared then after aggregates are added to the mix to produce high strength concrete. The achievement of higher compressive strength is associated with the efficiency of cement particles and water saved in the accurate mixing of cement paste.

Inhibition or Prevention of Cracks

This is another technique by which high strength concrete is produced. Cracks development in concrete may cause failure if it expands. The replacement of 2-3% aggregate by polythene or polystyrene pieces of 0.025mm thick results into increased compressive strength.

Sulphur Filling or Impregnation

This is the method where impregnation of sulphur into low porous concrete is done to produce high strength of concrete. The impregnation process of concrete in the laboratory involves moist cured fresh concrete for 24hours, dry specimens at 120C for 24hours, the immersion of the specimens in molten Sulphur under vacuum for two hours and then a release of the vacuum after two hours. The samples are then kept in molten Sulphur for half an hour.

Use of Cementitious Aggregates

The use of cementitious aggregates, such as fondu can produce high-strength concrete. The fondu aggregate is a glassy slag clinker cementitious material.

Seeding

Seeding is a less practical method of producing high-strength concrete. It includes adding a small percentage of finely ground, fully hydrated Portland cement to the fresh concrete mix.

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