burnt clay jellies

IS 7556: Scope & Key Specifications

• Scope: This standard applies to dimensions, tolerances, and definitions related to the product, referencing IS 2248-1981 for terminology.

• Definitions: As per IS 2248-1981.

• Rounding Off: Use IS 2-1960 for rounding test or analysis results to the same significant figures as specified values.

Dimensions and Tolerances (Clause 3.2)

• Tolerances apply to 20 Jallies (units/items).

Notes:

• The table indicates permissible dimensional deviations to ensure uniformity.
• For precise design or manufacturing, always refer to the full IS 7556 and IS 2248 documents.

flowchart TD
    A[Start: Product Dimension] --> B{Dimension Range?}
    B -->|190-140 mm| C[Tolerance ±80 mm]
    B -->|90 mm| D[Tolerance ±40 mm]
    B -->|Others| E[Check IS 7556 for details]

IS 7556 - Definitions Summary

• Reference Standard: All definitions in IS 7556 refer to IS 2248:1981 (Glossary of terms relating to clay products for building).

• Rounding Off: Test or analysis results must be rounded per IS 2:1960 rules, retaining the same number of significant digits as the specified value.

• Dimensions & Tolerances:

  • Thickness of shells, webs, and void areas are specified in Clause 3.3 (see IS 7556 for exact dimensional limits).

• International Coordination: The standard aligns with global practices and adapts to Indian construction norms.

Key Points to Note:

For detailed definitions, consult IS 2248:1981 directly.
For rounding rules, refer to IS 2:1960.

flowchart LR
    A[IS 7556 Definitions] --> B[IS 2248:1981 (Glossary)]
    A --> C[IS 2:1960 (Rounding Rules)]
    A --> D[Clause 3.3 (Thickness & Voids)]

This ensures clarity and uniformity in interpretation across clay building products.

IS 7556: Dimensions and Tolerances for Jallies

Key Specifications (Clause 3.2)

• Note: Tolerances are based on measurements from a minimum of 20 jallies.
• Dimensions should be rounded off as per IS 2:1960 for compliance decisions.
• Definitions follow IS 2248:1981.

Additional Notes:

• Tolerances ensure manufacturing consistency.
• Measurement accuracy affects structural performance.
• Use average breaking load (N/mm) for quality checks.

flowchart LR
    A[Measure Dimensions of 20 Jallies] --> B{Dimension Range?}
    B --> |190-140 mm| C[±80 mm Tolerance]
    B --> |90 mm| D[±40 mm Tolerance]
    B --> |Others| E[Refer IS 7556 Full Table]
    C & D & E --> F[Check Compliance with IS 2:1960 Rounding]

For full tables and detailed tolerances, refer to the complete IS 7556 document.

IS 7556: General Quality - Key Points

• Rounding Off (Clause 0.4):
  Final test/analysis values must be rounded per IS 2-1960 rules.

  • Retain the same number of significant figures as the specified value.

• International Coordination (Clause 0.3):
  Standard aligns with international practices and local field conditions.

• Keys for Bonding (Clause 3.4):

  • Width = 10 mm
  • Depth = 3 mm

• Dimensional Tolerances (Clause 3.2, Table 3):

Note: The table in the context is incomplete; typical tolerances reduce with smaller dimensions.

Summary Diagram of Key Dimensions and Tolerances

graph LR
A[Dimensions] --> B[140-190 mm: ±80 mm]
A --> C[90-100 mm: ±40 mm]
A --> D[Keys: 10 mm wide, 3 mm deep]

Use these specifications to ensure compliance with IS 7556 quality requirements.

IS 7556: Physical Requirements - Key Points

1. Test Specimen (Clause 2.0 & A-1)

• Definitions as per IS 2248:1981 apply.
• Specimen: Jalli (wire mesh) tested for breaking load.

2. Dimensions and Tolerances (Clause 3.2)

3. Method of Determination of Breaking Load (Clause 5.1 & A-4.1)

• Support jalli vertically on cylindrical steel beams.
• Span = 3/4 × Length of jalli.
• Use packing for uniform load distribution.
• Load applied perpendicularly at a uniform rate: 300 to 400 N/min.

4. Reporting (A-5)

• Document breaking load and test conditions clearly.

Summary Diagram: Load Application Setup

graph LR
A[Jalli Specimen] -- Vertically Supported --> B[Cylindrical Steel Beams]
B -- Span = 3/4 Length --> C[Support Points]
D[Load] -- Applied Perpendicular --> A

This setup ensures accurate breaking load measurement under standardized conditions.

IS 7556: Sampling Key Points

• Sampling Procedure:
  Sampling of jallies must follow IS 5454-1978. This ensures representativeness and consistency.

• Sample Size:
  Use 5 to 15 jallies depending on the lot size (Clause 1.1).

• Test Result Reporting:
  Calculate and report the average absorption percentage of all specimens (Clause 3.2).

• Rounding Off:
  Final test values must be rounded as per IS 2-1960 with the same significant figures as the specified standard values (Clause 0.4).

Summary Table for Sampling

If you need detailed sampling steps, refer to IS 5454-1978 which covers lot size, random selection, and sample handling.

IS 7556: Marking of Clay Jallis — Key Points

• Marking Requirements (Clause 7.1):

  • Each clay jalli must be legibly and indelibly marked with:
    • Name of the manufacturer
    • Type of the jalli

• Standard Mark (Clause 7.1.1):

  • Jallis may bear the BIS Standard Mark.
  • This mark assures compliance with the standard under BIS inspection, testing, and quality control.
  • Use of the Standard Mark is governed by the Bureau of Indian Standards Act, 1986.
  • Licensing details for the Standard Mark can be obtained from BIS.

• Rounding Off Test Results (Clause 0.4):

  • Final test values should be rounded off as per IS 2-1960.
  • Retain the same number of significant digits as the specified value.

Summary Table for Marking

This ensures traceability and quality assurance for clay jallis under IS 7556.

IS 7556: Method for Determination of Breaking Load of Burnt Clay Jallies

Key Points from Clause 5.1 & Appendix A:

• Test Specimen: Dimensions and tolerances based on average measurements from at least 20 samples.
• Breaking Load Unit: Reported as N/mm width.
• Minimum Average Breaking Load:
  [ \text{Average Breaking Load} \geq 12 \text{ N/mm width} ]

Procedure Summary (Appendix A):

• Prepare specimens as per specified dimensions.
• Apply load gradually until the specimen breaks.
• Record breaking load for each specimen.
• Calculate average breaking load over all tested samples.

Formula for Average Breaking Load:

[ \text{Average Breaking Load} = \frac{\sum_{i=1}^{n} P_i}{n \times w} ]

Where:

• (P_i) = Breaking load of specimen (i) (in Newtons)
• (n) = Number of specimens tested
• (w) = Width of specimen (in mm)

Summary Table:

flowchart TD
    A[Prepare 20+ Specimens] --> B[Measure Width (w)]
    B --> C[Apply Load till Break]
    C --> D[Record Breaking Load (P_i)]
    D --> E[Calculate Average Breaking Load]
    E --> F{Is Average ≥ 12 N/mm?}
    F -- Yes --> G[Specimen Passes]
    F -- No --> H[Specimen Fails]

This method ensures quality control for burnt clay jallies as per IS 7556.

IS 7556: Water Absorption Test for Jallies

Key Specifications & Procedure

• Specimen Drying: Oven dry at 100–110°C until constant weight.
• Weigh Dry Specimen (A): After cooling.
• Immersion: Immerse specimen in potable water at 24–30°C for 24 hours.
• Weigh Wet Specimen (B): Wipe surface water and weigh within 3 minutes.

Formula for Water Absorption (%)

[ \text{Water Absorption} = \frac{B - A}{A} \times 100 ]

Where:

• A = Dry weight (g)
• B = Weight after 24 h immersion (g)

Acceptance Criteria

• Average water absorption of jallies ≤ 15%.

Summary Table

flowchart TD
    A[Dry Specimen in Oven (100-110°C)] --> B[Weigh Dry Specimen (A)]
    B --> C[Immerse in Water (24-30°C) for 24h]
    C --> D[Remove & Wipe Surface]
    D --> E[Weigh Wet Specimen (B)]
    E --> F[Calculate Water Absorption: ((B - A)/A)*100]
    F --> G{Is Absorption ≤ 15%?}
    G -- Yes --> H[Specimen Acceptable]
    G -- No --> I[Specimen Rejected]

This ensures compliance with IS 7556 water absorption requirements.

IS 7556: Method of Testing Efflorescence on Jalli

Test Procedure (Clause 5.3 & Appendix C)

• Specimen Preparation: Place the jalli upright in a dish with 25 mm water depth.
• Environment: Keep in a warm, well-ventilated room at 20–30°C.
• Cycle: Allow water to evaporate completely; when dry, re-immerse with the same water depth.
• Observation: After the second drying, examine for efflorescence.

Efflorescence Rating (Clause 5.3)

• Acceptable Limit: Efflorescence shall be 'slight', meaning:
  • Not more than 10% of total surface area (internal + external) is covered.
  • Salt deposit should be a thin layer only.

Specimen Conditioning (Clause 2.1)

• Dry specimens in oven at 100–110°C until constant weight.
• Cool, weigh, then immerse in potable water at 24–30°C for 24 hours.
• Remove, wipe surface water, and weigh within 3 minutes.

Summary Table

flowchart TD
    A[Place jalli upright in dish] --> B[Add 25 mm water]
    B --> C[Keep at 20-30°C until water evaporates]
    C --> D[Water absorbed, jalli dry]
    D --> E[Add same quantity of water]
    E --> F[Allow absorption and drying]
    F --> G[Examine for efflorescence]
    G --> H{Efflorescence ≤ 10%?}
    H -- Yes --> I[Pass]
    H -- No --> J[Fail]

This method ensures standardized evaluation of efflorescence on jalli surfaces per IS 7556.