Prestressed concrete poles for overhead power, traction and telecommunication lines

Scope of IS 1678:

• Defines testing and conformity criteria for poles (likely wooden or similar structural poles).
• Applies to sampling, testing, and acceptance of poles in lots.

Key Specifications and Tables

Sampling and Acceptance (Clause 9.2.1, Table 9.2):

• If failure occurs in transverse strength tests, double the sample size is retested.
• Passing retest means lot acceptance; failure means rejection.

Rounding Off (IS 2:1960)

• Final test or analysis values are rounded to the same number of significant figures as specified in IS 1678.

Notes:

• Refer to Annex A for related Indian Standards.
• Always check for the latest editions of referenced standards.

flowchart TD
    A[Lot of Poles] --> B[Sample Selection]
    B --> C{Test Poles for Dimensions}
    C -->|Pass| D[Test Transverse Strength]
    C -->|Fail| E[Reject Lot]
    D --> F{Pass Ultimate Strength?}
    F -->|Yes| G[Accept Lot]
    F -->|No| H[Retest Double Sample]
    H --> I{Pass Retest?}
    I -->|Yes| G
    I -->|No| E

This summarizes the scope, sampling, testing, and acceptance criteria as per IS 1678.

IS 1678 references several key Indian Standards (Annex A) essential for concrete and prestressed concrete design and materials:

Important Notes:

• Use the latest editions of these standards for design and material specifications.
• Rounding of test values must follow IS 2:1960 rules.
• Certification and marking governed by BIS Act 1986 (Clause 10.2.1).

Example: Rounding off per IS 2:1960

If specified value = 25.0, round test result to one decimal place (e.g., 24.97 → 25.0).

IS 1678: Key Definitions and Sampling Specifications

Definitions (Clause 3.0)

• The standard defines terms related to prestressed concrete poles to ensure uniform understanding.
• Final test results must be rounded per IS 2:1960 rules, maintaining the same significant figures as specified.

Sampling & Testing (Clause 9.2.1, Table 9.2)

For lot size and sample size, the table specifies:

• If failures occur in transverse strength tests, double the original sample is retested.
• Passing retests means the lot is accepted.

Notes

• Refer to Annex A for related Indian Standards.
• Always use the latest editions for compliance.

flowchart TD
    LotSize --> SampleSize
    SampleSize --> DimensionalTest[Dimensional Requirements Test]
    SampleSize --> TransverseTest[Transverse Strength Test]
    DimensionalTest --> AcceptanceCheck
    TransverseTest --> AcceptanceCheck
    AcceptanceCheck -->|Pass| LotAccepted[Lot Accepted]
    AcceptanceCheck -->|Fail| Retest[Retest Double Sample]
    Retest -->|Pass| LotAccepted
    Retest -->|Fail| LotRejected[Lot Rejected]

This ensures quality control and compliance with IS 1678 standards.

IS 1678: Overall Length and Dimensions of Poles

1. Overall Length of Poles (Clause 4.1)

• Minimum length: 6.0 m
• Length increments: 0.5 m steps (e.g., 6.0, 6.5, 7.0 m, etc.)

2. Depth of Planting (Clause 6.3, Table 1)

• Actual depth depends on ground conditions.

3. Working Load Location (Clause 3.7)

• Maximum transverse load acts 600 mm below the top of the pole.

4. Hole Specifications (Fig. 1)

• All holes (for earthing, danger plates, etc.) are 20 mm diameter unless otherwise specified.

Summary Diagram of Pole Dimensions

graph TB
  A[Top of Pole]
  B[Load Point (600 mm below top)]
  C[Ground Level]
  D[Depth of Planting]
  E[Butt End of Pole]

  A -->|600 mm| B
  B -->|Length - (0.6 m + Depth of Planting)| C
  C -->|Depth of Planting (Table 1)| D
  D --> E

This ensures poles are designed with proper length, planting depth, and load considerations per IS 1678.

IS 1678: Key Specifications & References for Materials

1. Materials Covered:

• Coarse and fine aggregates (IS 383:1970)
• Portland slag cement (IS 455:1989)
• Ordinary Portland cement (IS 8112:1989 for 43 grade, IS 12269:1987 for 53 grade)
• High tensile steel bars (IS 2090:1983)
• Mild and medium tensile steel bars (IS 432 Part 1 & 2:1982)
• Hard drawn steel wire (IS 1785 Part 1 & 2:1983)
• Prestressed concrete wires and strands (IS 2905:1989, IS 6003:1983, IS 6006:1983, IS 14268:1995)
• Admixtures for concrete (IS 9103:1979)

2. Sampling & Testing (Clause 9.2.1):

• If failures occur, double the sample size is tested.
• All poles must meet dimensional and strength criteria.

3. Rounding Off (IS 2:1960):
Final test values must be rounded to the same significant figures as specified.

Summary Diagram: Material Standards & Testing Flow

flowchart TD
    A[Materials] --> B[Aggregates (IS 383)]
    A --> C[Cements (IS 455, 8112, 12269)]
    A --> D[Steel Bars & Wire (IS 432, 1785, 2090)]
    A --> E[Prestressing Wires (IS 2905, 6003, 6006)]
    A --> F[

IS 1678 - Design Requirements Summary

1. Sampling & Testing (Clause 9.2.1, Table 9.2)

• If failure occurs in transverse strength test, double the sample size retested.
• Lot passes if no failures in retest.

2. Depth of Planting (Clause 6.3, Table 6.3)

• Actual depth depends on ground conditions.

3. Rounding Off (IS 2:1960)

• Final test values must be rounded off to the same decimal places as specified values.

Key Notes:

• Applies to prestressed concrete poles with pretensioning.
• Includes requirements for earthing.
• Ensures quality control via sampling and strength testing.
• Depth of planting critical for stability.

flowchart TD
    A[Lot of Poles] --> B{Sample Size per Table}
    B --> C[Dimensional Test]
    B --> D[Transverse Strength Test]
    C -->

IS 1678 - Manufacture Key Points

1. Rounding Off (IS 2:1960)

   • Test results shall be rounded off as per IS 2 rules, matching significant figures of specified values.

2. Testing During Manufacture (Clause 8.1)

   • Concrete tests as per Clause 7.9 must be conducted during manufacturing to ensure quality.

3. Certification Marking (Clause 10.2.1)

   • Use of BIS Standard Mark follows Bureau of Indian Standards Act, 1986.
   • Manufacturers must comply with licensing conditions for marking.

4. Referenced IS Standards (Annex A)

   • Manufacturing involves materials conforming to related IS codes, e.g.:
     • IS 383: Aggregates for concrete
     • IS 432: Mild steel bars for reinforcement
     • IS 455: Portland slag cement
     • IS 456: Code of practice for plain and reinforced concrete
     • IS 875 (Part 3): Wind loads
     • IS 1343: Prestressed concrete
     • IS 1786: High strength deformed steel bars

Typical Concrete Test Parameters During Manufacture (per IS 1678 & IS 456):

Summary Flowchart of Manufacture Quality Control

flowchart TD
    A[Raw Material Inspection] --> B[Mix Design Verification]
    B --> C[Concrete Mixing]
    C --> D[Sampling & Testing (Clause 7.9)]
    D --> E{Test Results}
    E -->|Pass| F[Batch Approved]
    E -->|Fail| G[Investigate & Adjust Process]

Note: For detailed manufacturing procedures, refer to IS 456 and related referenced standards listed in Annex A of IS 1678.

IS 1678 - Testing: Key Formulas, Tables & Specifications

1. Sampling & Acceptance Criteria (Clause 9.2.1, Table 2)

• If failure occurs in transverse strength test, double the original sample and retest.
• If no failure in retest, lot passes.

2. Testing Notes (Clause 9.2.2)

• Transverse strength tests are mandatory on sample size per Table 2.
• Poles tested must meet strength requirements in Clause 8.2.
• Final test values must be rounded per IS 2:1960.

3. Hole Specifications (Fig. 1)

• All holes except specified are 20 mm diameter.
• Holes for earthing, danger plate, and number plate have specific provisions.
• Use hardwood plugs for plugging holes.

Summary:
Use Table 2 for sampling size and acceptance numbers. Test transverse strength on the sample; if failure occurs, double sample size and retest. Follow IS 2:1960 for rounding off test results. Holes mostly 20 mm diameter with specific provisions.

flowchart TD
    A[Lot of Poles] --> B[Select Sample per Table 2]
    B --> C[Dimensional Test]
    C -->|Pass| D[Transverse Strength Test]
    D -->|Pass| E[Lot Accepted]
    D -->|Fail| F[Double Sample Size & Retest]
    F -->|Pass| E
    F -->|Fail| G[Lot Rejected]

IS 1678: Sampling and Inspection Key Points

1. Scale of Sampling (Clause 9.1)

• Sampling size depends on the lot size of poles.
• Sample poles are selected randomly for testing.

2. Number of Tests & Criteria for Conformity (Clause 9.2.1 & Table 9.2)

• Acceptance Number: Maximum allowable defective poles in the sample.
• If any pole fails the transverse strength test, double the original sample is retested.
• If no failures in retest, the lot passes.

3. Rounding Off (Clause None)

• Follow IS 2:1960 for rounding test results.
• Maintain the same significant figures as specified values.

Summary Flow for Testing Lot:

flowchart TD
    A[Select Sample Size based on Lot] --> B[Test Dimensional & Strength]
    B --> C{Failures?}
    C -- No --> D[Lot Accepted]
    C -- Yes --> E[Double Sample Size Retest]
    E --> F{Failures?}
    F -- No --> D
    F -- Yes --> G[Lot Rejected]

This ensures quality control by statistically verifying conformity of poles in a lot.

IS 1678: Marking and Certification Key Points

1. Marking Requirements (Clause 10.1)

Poles must be clearly and indelibly marked before testing at a visible position after erection with:

• Source of manufacture
• Month and year of manufacture
• Serial number
• Position of centre

2. BIS Certification Mark (Clause 10.2)

• Poles may bear the BIS Standard Mark.
• Use governed by BIS Act, 1986 and related rules.
• Licence conditions for Standard Mark use available from BIS.

3. Sampling and Testing (Clause 9.2.1 - Table 2)

• If failures occur, double the sample size for retesting.
• No failures in retest means lot acceptance.

Summary Diagram: Marking & Certification Flow

flowchart TD
    A[Manufacture of Poles] --> B[Marking as per Clause 10.1]
    B --> C[Testing (Dimensional & Strength)]
    C --> D{Pass?}
    D -- Yes --> E[Apply BIS Standard Mark (Optional)]
    D -- No --> F[Retest with Double Sample]
    F --> G{Pass Retest?}
    G -- Yes --> E
    G -- No --> H[Reject Lot]

For detailed conditions on BIS mark usage, consult the Bureau of Indian Standards directly.

IS 1678 - List of Referenced Indian Standards (Annex A)

This standard references key Indian Standards essential for concrete and prestressed concrete design and materials:

Key Notes:

• These standards cover materials (cement, steel, aggregates), design codes, testing, and handling.
• Always verify the latest editions from BIS as standards are periodically revised.
• Certification and use of BIS Standard Mark follow Bureau of Indian Standards Act, 1986 (Clause 10.2.1).

Example: Aggregate Specification (IS 383:1970)

• Coarse Aggregate Size: 20 mm nominal maximum size usually used.
• Fineness Modulus: 6.75 to 7.5 for coarse aggregates.
• Specific Gravity: 2.6 to 2.9 typical for natural aggregates.

graph LR
A[IS 1678] --> B[IS 456:1978

IS 1678: Technical Committee Composition & Key Specifications

Technical Committee Composition (Annex B):
The Cement Matrix Products Sectional Committee, CED 53, is responsible for this standard.

• Chairman: Shri S. A. Reddi (Gammon India Ltd)
• Members: Representatives from Municipal Corporations, Construction Companies, Research Institutes, BIS, and Industry Associations.
• Includes alternates for continuity and expertise.

Key Tables & Specifications

• If failures occur, double the original sample is retested. Zero failures in retest means the lot passes.

Additional Notes

• Use of BIS Standard Mark follows the Bureau of Indian Standards Act, 1986 (Clause 10.2.1).
• Refer to Annex A for related IS codes on materials and testing methods (e.g., IS 383 for aggregates, IS 456 for concrete practice).

flowchart TD
    A[Technical Committee (CED 53)] --> B[Chairman: Shri S. A. Reddi]
    A --> C[Members: Industry, Govt, Research]
    D[Lot Sampling] --> E[Sample Size per Lot]
    E --> F[Dimensional Tests]
    E --> G[Transverse Strength Tests]
    F --> H[Accept/Reject]
    G --> H
    H --> I{Failures?}
    I -- Yes --> J[Double Sample Retest]
    I -- No --> K[Lot Accepted]
    J --> K

For detailed committee member list and roles, refer to Annex B of IS 1678.