Role of Admixture in Precast Concrete

G. Shivaprakash, M – Tech Structure, Product Segment Managers, Fosroc Chemicals (India) Limited, Bangalore

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Precast Construction system is an upcoming construction technique in India to speed up the process of construction to reduce construction days and early hand over. Precast product resulted from concrete in a reusable molds and cured in control environment. These precast products are then transported to construction site and lifted into place.

Governing factors in precast concrete

• Low water-cement ratio.
• Medium workability.
• Very high water reducing admixture.
• Need for high early strength for early de-moulding to increase productivity.
• Compatibility with cement replace- ments.
• Compatibility with 100% crushed sand / manufactured sand.

Fosroc offer Auracast product range to suit current requirements.
Auracast 100 is a low-viscosity, single component PCE-based admixture for low slump concrete that enables obtaining of 50% of the characteristic strength in 24 hours. This makes it an ideal admixture for precast segments such as underground metro rings and precast walls and slabs for buildings.

Auracast 270M is a low-viscosity,, single component PCE-based admixture for normal slump concrete with slump retention and enables obtaining of 50% of the characteristic strength in 24 hours, This makes it ideal for large volume of concreting in precast industries.

Auracast 405 is a low-viscosity, single component PCE-based admixture for flow concrete with slump retention. It enables obtaining 50% of the characteristic strength in 24 hours. This makes it an ideal choice for concrete poured in structures having congested reinforcement and tunnel forming etc.

All Product complies with IS 9103 and ASTM C 404 Type F

Advantage:
Strength
Requirement of high early strength is a prime requirement of hardened concrete to increase the productivity by all means. Our Auracast product range enables to obtain required streng Shrinkage

Applications:

• Pre-fabricated high rise buildings.
• Metro rail construction.
• Road and railway bridges
• Precast elements such as barricades for roads and water splash area.
• Railway sleepers