What is the main purpose of using a superplasticizer?

To produce flowing concrete for easy placement without adding extra water, or to produce high-strength concrete by significantly reducing the water-cement ratio while maintaining workability (Clause 1.1).

What is the minimum required water reduction for an admixture to be classified as a superplasticizer?

A minimum of 20% compared to the control mix (Table 1).

How much should the 3-day strength of superplasticized concrete increase?

It should be at least 140% of the compressive strength of the control concrete mix (Table 1).

Is this standard still active?

No, this standard has been superseded and its contents are now covered under IS 9103:1999 (Specification for Concrete Admixtures).

IS 12262

: 1987

Use of Superplasticizing Admixtures in Concrete - Guidelines

CurrentSpecializedGuidelinesMaterials Science · Precast and Prefabricated Concrete

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This standard provides guidelines for using superplasticizing admixtures in concrete to produce high workability (flowing) concrete or high-strength concrete with reduced water content. It specifies the physical and chemical requirements for these admixtures, along with guidance on trials, dosage, and precautions during use.

Provides guidelines for the proper use of superplasticizing admixtures in concrete to improve workability or reduce water content.

Quick Reference Values

Minimum Water Reduction20%

Minimum Compressive Strength (3 days vs Control)140%

Minimum Compressive Strength (7 days vs Control)115%

Minimum Compressive Strength (28 days vs Control)115%

Initial Setting Time Variation from ControlNot more than 30 minutes before

Final Setting Time Variation from ControlNot more than 60 minutes before

Chloride Content (Max)0.2% by mass of admixture

Practical Notes

Always conduct site trials with actual project materials (cement, aggregates) to determine the optimum dosage and to check for adverse effects like segregation or excessive setting time changes.

The slump-enhancing effect is temporary. Ensure concrete is transported, placed, and compacted within the window of increased workability, which can be as short as 30-60 minutes.

Overdosing can lead to severe segregation and retardation. Admixtures should be dispensed using a calibrated dispenser for accuracy.