What is the main purpose of adding fibres to concrete?

To control cracking and significantly enhance post-crack behavior, including toughness, ductility, and energy absorption capacity (Clause 5).

What is a typical dosage of steel fibres for industrial flooring?

Approximately 20 to 30 kg/m³, which corresponds to about 0.25% to 0.4% by volume (Table 2).

What is the recommended maximum aggregate size for FRC?

Generally 10 mm to 12.5 mm to ensure good workability and uniform distribution of fibres throughout the concrete matrix (Clause 6.2).

How is the performance of FRC measured?

Primarily through flexural toughness tests as per ASTM C1018, which measures the post-crack energy absorption, a key performance indicator (Clause 5.3).

IS 14897

: 2000

Recommendations for use of fibre reinforced concrete

CurrentSpecializedGuidelinesBIMMaterials Science · Tunneling and Underground Structures

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This standard provides recommendations for the use of fibre reinforced concrete (FRC), covering materials, properties, mix design, and applications. It serves as a guide for using steel, synthetic, and other fibres to enhance concrete's toughness, ductility, and crack control in applications like shotcrete, tunnels, and industrial pavements.

Provides recommendations for the design, properties, and applications of fibre reinforced concrete.

Quick Reference Values

Typical fibre volume fraction0.5% to 2.0%

Typical aspect ratio (L/d) for steel fibres30 to 100

Maximum nominal aggregate size for FRC10 mm to 12.5 mm

Typical steel fibre dosage for shotcrete30 to 40 kg/m³

Minimum cementitious material content for FRC350 kg/m³

Practical Notes

Fibre 'balling' is a common problem; ensure fibres are added gradually to the mix, often with aggregates, to achieve uniform distribution.

The primary benefit of FRC is enhanced post-crack performance (toughness and energy absorption), not a significant increase in compressive or flexural strength.

Standard slump tests are often not suitable for FRC; workability should be assessed using methods like the inverted slump cone test or VeBe time, as recommended in the code.