What types of strands are covered in this standard?

Two-wire, three-wire, and seven-wire uncoated stress-relieved strands (Clause 1.1).

What is the minimum breaking strength for a 12.7 mm seven-wire strand?

129.5 kN, as specified in Table 2.

What is the requirement for elongation?

The minimum elongation at fracture must be 3.5 percent on a gauge length of 600 mm (Clause 10.1).

Is a light coating of rust on the strand acceptable?

Yes, a light film of rust that can be removed by wiping with a dry cloth is not a cause for rejection (Clause 6.1, Note).

IS 6006

: 1983

uncoated stress-relieved strand for prestressed concrete

CurrentFrequently UsedSpecificationBIMMaterials Science · Concrete Reinforcement (Steel)

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This standard specifies the requirements for uncoated, stress-relieved, low relaxation steel strands used for prestressing concrete. It covers two-wire, three-wire, and seven-wire strands, detailing their manufacturing, dimensions, mechanical properties like breaking strength and elongation, and testing procedures.

uncoated stress-relieved strand for prestressed concrete

Quick Reference Values

Minimum breaking strength of 15.2 mm seven-wire strand182.0 kN

Minimum breaking strength of 12.7 mm seven-wire strand129.5 kN

Minimum elongation at fracture (on 600 mm gauge length)3.5 %

Maximum 1000-h relaxation at 70% of min breaking strength5.0 %

Nominal diameter of largest seven-wire strand15.2 mm

Practical Notes

This version of the code has been superseded by IS 6006:2014 and should not be used for new projects. Always refer to the latest version.

Ensure strands are free from loose rust, oil, and other contaminants before use to ensure a proper bond with concrete. A light film of rust that can be wiped off is generally acceptable.

The relaxation properties are critical for long-term performance and calculating prestress losses. Always verify supplier test certificates for compliance.