stone lintels

IS 9394 - Scope & Key Specifications for Stone Lintels

Scope Highlights:

• Applies to stones used for lintels with specific physical properties.
• Final test/analysis values must be rounded as per IS 2:1960.
• Dimensional tolerances:
  • ±1.5 mm for dimensions ≤ 1.2 m
  • ±3 mm for dimensions > 1.2 m

Key Physical Properties (Table 1):

Notes:

• These properties ensure lintel stones withstand structural loads and environmental effects.
• Testing must follow the referenced IS standards for accuracy.

flowchart TD
    A[Stone Lintel] --> B[Physical Properties]
    B --> C[Specific Gravity ≥ 2.6]
    B --> D[Water Absorption ≤ 1%]
    B --> E[Transverse Strength ≥ 11 N/mm²]
    B --> F[Durability: No cracks/spalling]
    A --> G[Dimensional Tolerance]
    G --> H[±1.5 mm (≤1.2m)]
    G --> I[±3 mm (>1.2m)]

This concise summary covers the scope and key specifications from IS 9394 for stone lintels.

IS 9394: General Requirements for Stone Lintels

Key Physical Properties (Clause 3.1, Table 1)

Quality Control (Clauses 8.3 & 8.4)

• Inspection: Check lintels for general requirements, transverse strength, dimensions, tolerances, and workmanship.
• Defect Limits: Refer to Table 2 (not provided) for permissible defective numbers per lot.
• Sampling: Random sub-sampling per Table 2 for physical property testing.
• Acceptance: Lot passes if defective lintels ≤ permissible number and no failures in physical tests.

Summary Diagram

flowchart TD
    A[Select Lot of Lintels] --> B[Check General Requirements]
    B --> C{Defective Count ≤ Permissible?}
    C -- Yes --> D[Test Physical Properties on Sub-sample]
    C -- No --> E[Reject Lot]
    D --> F{Any Failures?}
    F -- No --> G[Accept Lot]
    F -- Yes --> E

Note: Refer to IS 9394 Table 2 for sampling sizes and defect limits.

IS 9394: Physical Properties of Stones for Lintels

Sampling & Testing (Clause 8.4)

• After passing dimensional and strength checks, a random sub-sample (per Table 2) is tested for physical properties.
• Lot acceptance: No failures in the physical property tests.

Additional Notes:

• Stones damaged by blasting, heating, or driving edges are not rejected (Clause 2.4).
• Values are rounded per IS 2-1960 rules to match specified significant figures.

Summary Diagram

flowchart TD
    A[Stone Lot] --> B{Dimensions & Strength OK?}
    B -- Yes --> C[Random Sub-sample Selection]
    C --> D[Test Physical Properties]
    D --> E{Any Failures?}
    E -- No --> F[Lot Accepted]
    E -- Yes --> G[Lot Rejected]

This ensures lintel stones meet minimum quality for durability and strength.

IS 9394: Dimensions and Tolerances Summary

• Tolerance Limits (Clause 4.3):

  • For dimensions ≤ 1.2 m: ± 1.5 mm
  • For dimensions > 1.2 m: ± 3 mm

• Rounding Off (Clause 0.4):

  • Follow IS 2-1960 for rounding test/analysis results.
  • Retain significant figures equal to those specified in the standard.

• Quality Control (Clause 8.3):

  • Lintels must comply with dimensions & tolerances per Clause 4.
  • Defective lintels exceed permissible limits in Table 2 → lot rejected.

Quick Reference Table for Tolerances

Notes:

• Dimensions refer to overall lintel sizes (length, width, height).
• Ensure workmanship and transverse strength also comply (see Clauses 3, 6).
• Use IS 1121 (Part II) for transverse strength test methods.

flowchart TD
    A[Lintel Dimensions] --> B{Length ≤ 1.2 m?}
    B -- Yes --> C[Tolerance ±1.5 mm]
    B -- No --> D[Tolerance ±3 mm]
    C & D --> E[Check workmanship & strength]
    E --> F{Defective?}
    F -- No --> G[Lot Accepted]
    F -- Yes --> H[Lot Rejected]

This ensures lintel dimensional accuracy and quality per IS 9394.

IS 9394: Design Requirements for Stone Lintels

Key Physical Properties (Table 1)

Additional Specifications

• Rounding Off: Test results should be rounded per IS 2:1960, maintaining the same significant figures as specified.
• Quality Control: Lintels must be checked for general requirements, transverse strength, dimensions, tolerances, and workmanship (Clause 8.3).
• Defect Limits: A batch is acceptable if defective lintels do not exceed permissible limits (refer Table 2 in IS 9394).

Summary Diagram of Compliance Check

flowchart TD
    A[Select Lintel] --> B[Check General Requirements]
    B --> C[Test Transverse Strength]
    C --> D[Measure Dimensions & Tolerances]
    D --> E[Inspect Workmanship]
    E --> F{Defects ≤ Permissible Limit?}
    F -- Yes --> G[Lintel Accepted]
    F -- No --> H[Lintel Rejected]

This ensures lintels meet durability, strength, and quality standards for safe structural use.

Workmanship Requirements as per IS 9394

• Inspection: All lintels selected per Table 2 (Clause 8.3) must be checked for:

  • General requirements
  • Transverse strength
  • Dimensions & tolerances (±1.5 mm for ≤1.2 m, ±3 mm for >1.2 m, Clause 4.3)
  • Workmanship quality

• Defect Criteria: Any lintel failing any above is defective. Lot acceptance depends on permissible defectives (Table 2, col 3).

• Sampling Details (Clause 8.2 & Table 2):

• Acceptance: If defective lintels ≤ permissible number, lot is accepted for workmanship and dimensions.

• Random Sampling: Sub-samples are tested for physical properties (Clause 8.4).

Summary:

• Workmanship quality is verified through visual and dimensional checks.
• Tolerance: ±1.5 mm (≤1.2 m), ±3 mm (>1.2 m).
• Sampling & acceptance per Table 2 ensures quality control.

flowchart TD
    A[Select Lot] --> B[Sample lintels per Table 2]
    B --> C[Check workmanship, dimensions, strength]
    C -->|No defects > permissible| D[Accept Lot]
    C -->|Defects > permissible| E[Reject Lot]
    D --> F[Test sub-sample for physical properties]
    F -->|Pass| G[Final Acceptance]
    F -->|Fail| E

IS 9394 — Marking of Stone Lintels

• Clause 7.1: Each stone lintel must be marked with the manufacturer's identification mark or initials in a suitable manner.

• Dimension Tolerances (Clause 4.3):

  • ±1.5 mm for dimensions ≤ 1.2 m
  • ±3 mm for dimensions > 1.2 m

• Rounding off (Clause 0.4): Test or analysis results must be rounded as per IS 2-1960, retaining the same significant figures as specified values.

Summary Table for Tolerances

Key Notes:

• Marking ensures traceability.
• Tolerances maintain dimensional accuracy.
• Follow IS 2-1960 for rounding off numerical results.

flowchart LR
    A[Stone Lintel] --> B[Mark with Manufacturer ID]
    A --> C[Measure Dimensions]
    C --> D{Dimension ≤ 1.2 m?}
    D -- Yes --> E[Tolerance ±1.5 mm]
    D -- No --> F[Tolerance ±3 mm]
    E & F --> G[Final Product]

This ensures compliance with IS 9394 marking and dimensional standards.

IS 9394: Sampling and Testing of Stone Lintels

1. Sampling Procedure (Clause 8.2 & 8.4)

• Sample size depends on lot size (Table 2).
• Sub-sample size for physical property tests is from column 4 of Table 2.
• Use random number tables (IS 4905-1968) for random selection.

2. Testing Criteria (Clause 8.4)

• Lot passes if no lintel in the sample fails any test.
• Tests include dimensions, workmanship, transverse strength, and other physical properties.

3. Rounding Off Results (Clause 0.4)

• Follow IS 2-1960 for rounding test results.
• Retain the same number of significant digits as specified values.

flowchart TD
    A[Lot of Lintels] --> B[Select Sample Size per Table 2]
    B --> C[Random Selection (IS 4905)]
    C --> D[Check Dimensions, Workmanship, Transverse Strength]
    D --> |Pass| E[Select Sub-Sample for Physical Tests]
    D --> |Fail| F[Reject Lot]
    E --> G[Perform Physical Property Tests]
    G --> |No Failures| H[Lot Accepted]
    G --> |Any Failure| F

This ensures statistically valid quality control for stone lintels per IS 9394.