Uncoated stress relieved low relaxation seven-ply strand for prestressed concrete -

IS 14268: Scope - Key Specifications & Tables

IS 14268 covers physical and mechanical properties of prestressing steel strands used in concrete.

Key Tables:

Table 1: Physical Properties (Clause 6.2.2)

• Breaking Strength = Maximum tensile strength of strand.
• 0.2% Proof Load = 90% of breaking strength (elastic limit).

Table 2: Dimensions, Tolerances & Mass (Clause 6.1)

IS 14268 Key References, Formulas & Tables Summary

1. Physical Properties (Clause 6.2.2, Table 1)

2. Dimensions, Tolerances & Mass (Clause 6.1, Table 2)

IS 14268: Definitions - Key Tables & Specifications

1. Definitions Reference

• Clause 3.0 refers to definitions from IS 1956 Parts 1, 2, 3, and 5 (1975-1976) for terms related to strands and steel products.
• These include terms on steel making, hot rolled steel, and iron.

2. Physical Properties of Strands (Table 1, Clause 6.2.2)

3. Dimensions, Tolerances & Mass (Table 2, Clause 6.1)

IS 14268: Manufacture - Key Specifications & Tables

1. Physical & Mechanical Properties (Clause 6.2)

• Breaking Strength (kN & kgs)
• 0.2% Proof Load = 90% of Breaking Strength

2. Dimensions, Tolerances & Mass (Clause 6.1)

IS 14268 - Chemical Composition: Key Points

IS 14268 primarily covers prestressing steel strands. Although explicit chemical composition tables are not provided in the given context, the standard references chemical analysis methods (e.g., IS 228 Part 9 for sulfur determination in carbon steel).

Chemical Composition Overview (Typical for Prestressing Strands)

• Carbon (C): ~0.70% max (high strength steels)
• Manganese (Mn): 0.60% - 1.00%
• Sulfur (S): ≤ 0.050% (controlled by IS 228 Part 9)
• Phosphorus (P): ≤ 0.050%
• Other elements (Si, Cr, Ni) are controlled to ensure mechanical properties.

Related Mechanical Properties (from Table 6.4)

Specifications Summary:

• Chemical analysis methods per IS 228 Part 9 for sulfur.
• Mechanical properties linked to chemical composition.
• Dimensional tolerances and mass per Table 2 (Clause 6.1).

Useful Formula: 0.2% Proof Load

[ \text{Proof Load} = 0.9 \times \text{Breaking Strength} ]

flowchart TD
    A[Steel Strand] --> B[Chemical Composition]
    B --> C[Carbon, Manganese, Sulfur, Phosphorus]
    A --> D[Mechanical Properties]
    D --> E[Breaking Strength]
    D --> F[0.2% Proof Load (90% of Breaking Strength)]
    B --> G[Chemical Analysis per IS 228 Part 9]

Summary: IS 14268 ensures chemical composition control via referenced IS methods, critical for achieving specified mechanical

IS 14268: Mechanical Properties Summary (Clause 6.2)

Key Specifications:

• Breaking Strength & 0.2% Proof Load (Clause 6.2.1, Table 1)
  Determined per IS 1521:1972; minimum values for strands:

• Nominal Diameter, Tolerance, Area & Mass (Clause 6.1, Table 2):

IS 14268: Sampling and Criteria for Conformity

Key Specifications:

• Test Gauge Length (Clause 6.4.8):
  Minimum gauge length = 40 × nominal strand diameter
  This ensures reliable tensile test results.

• Rounding Off (Clause 7):
  Final test values must be rounded per IS 2:1960, retaining the same number of significant digits as the specified value.

Sampling & Conformity Criteria (Clause 7.2 & 7.2.1):

• Initial Sampling: Test samples are taken from coils/strands as per agreed procedure.

• Failure Protocol:

  • If a sample fails any test, 2 additional samples from the same coil end are tested for the failed test(s).
  • If both additional samples pass, the coil complies.
  • If either additional sample fails, the coil does not comply.

Summary Table:

flowchart TD
    A[Initial Sample Test] -->|Pass| B[Coil Accepted]
    A -->|Fail| C[Take 2 Additional Samples]
    C --> D[Test Additional Samples]
    D -->|Both Pass| B
    D -->|Any Fail| E[Coil Rejected]

This ensures fair and statistically sound conformity assessment per IS 14268.

IS 14268: Marking and Packaging Key Points

Marking (Clause 9.1)

Each reel or reelless pack must have a label with:

• Source of manufacture
• Coil number
• Nominal diameter of strand
• Class (if applicable)

BIS Certification Marking (Clause 9.2)

• Use of the Standard Mark follows the Bureau of Indian Standards Act, 1986.
• Licensing conditions for Standard Mark usage are governed by BIS rules.
• Refer to Table 9.2 BIS Certification Marking (Clause 9.2.2) for marking details (not fully provided here).

Packaging

• Packaging should ensure protection against damage during transport and storage.
• Must maintain physical and mechanical properties as per Clause 6.2.

Summary Table for Marking Details

Notes:

• Marking ensures traceability and quality control.
• Packaging must prevent corrosion and mechanical damage.
• Always verify BIS license and Standard Mark authenticity.

flowchart TD
    A[Reel/Reelless Pack] --> B[Label]
    B --> C[Source of Manufacture]
    B --> D[Coil Number]
    B --> E[Nominal Diameter]
    B --> F[Class (if applicable)]
    A --> G[Packaging]
    G --> H[Protect from damage]
    G --> I[Maintain mechanical properties]

For detailed certification and licensing, contact BIS or refer to BIS Act, 1986.

IS 14268 - Certification Marking (Clause 9.2)

• Use of BIS Standard Mark is governed by the Bureau of Indian Standards Act, 1986.
• Licence for use of the Standard Mark is granted under conditions set by BIS.
• Each coil of strands should be marked with the BIS Standard Mark (Clause 9.2.1).
• For detailed licensing conditions, contact BIS directly.

Key Table Extracts for Strand Properties (Related to Marking & Identification)

Summary for Certification Marking:

• Marking on coils: Must include BIS Standard Mark.
• Licensing: Manufacturers must obtain permission from BIS.
• Purpose: Ensures product quality and traceability.

flowchart LR
    A[Manufacturer] --> B[Apply for BIS License]
    B --> C{License Granted?}
    C

IS 14268: Committee Composition Key Details

Committee: Concrete Reinforcement Sectional Committee, CED 54

Purpose: Formulation and review of standards related to concrete reinforcement.

Committee Composition (Annex A Summary)

Additional Notes:

• The committee includes technical experts, industry representatives, government engineers, and BIS officials ensuring comprehensive standard development.
• The committee operates under the Bureau of Indian Standards Act, 1986.
• No specific formulas or tables related to committee composition are provided; composition is descriptive.
• For licensing and certification details, refer to Clause 9.2.2 on BIS Certification Marking.

This structure ensures balanced representation for robust and practical standards in concrete reinforcement.