lime based blocks

IS 3115 - Scope: Key Points & References

Scope Summary:

• IS 3115 covers specifications for concrete blocks.
• Compliance is checked by rounding off test/calculated values per IS 2:1960.
• Blocks may carry the BIS Standard Mark ensuring quality control and conformity.
• The standard references multiple related IS codes for materials and testing, e.g., cement (IS 269), aggregates (IS 383), masonry units (IS 2185), and pozzolanic materials (IS 3812).

Important Specifications:

Notes on Use of Standard Mark:

• Indicates compliance with IS 3115.
• BIS supervises inspection, testing, and quality control.
• Licence for use of the Standard Mark is governed by BIS Act 1986.

Diagram: Compliance Process Flow

flowchart TD
    A[Block Production] --> B[Inspection & Testing]
    B --> C{Meets Dimensional & Visual Criteria?}
    C -- Yes --> D[Mark with BIS Standard Mark]
    C -- No --> E[Reject or Rework]
    D --> F[Lot Conforms to IS 3115]

For detailed material specs and testing procedures, refer to the full IS 3115:1992 document and related IS codes listed in Annex A.

IS 3115: Definitions & Key Specifications Summary

• Rounding Off (IS 2:1960):
  Final test or calculation values must be rounded to the same number of significant places as the specified value.

• Types of Blocks (Clause 5.7):

  • Type A: Both faces keyed for plastering.
  • Type B: Both faces smooth, suitable for use without plaster/render.
  • Type C: One face keyed, one face smooth.

• Water Quality:
  Must be fresh, clean, free from acids, alkalis, salts, or deleterious substances.

• Marking (Clause 14.2):
  Each block may carry the BIS Standard Mark ensuring compliance with IS 3115.

• Referenced IS Standards:
  Includes IS 269 (Portland cement), IS 383 (Aggregates), IS 2185 (Concrete masonry units), IS 455 (Portland slag cement), IS 3952 (Burnt clay bricks), etc.

Important Notes:

• The Standard Mark certifies quality under BIS inspection.
• Dimensions and tolerances are detailed in Clause 7 (not fully provided here).
• Use fresh water and appropriate block type for intended application.

flowchart TD
    A[Block Types] -->|Type A| B[Both faces keyed]
    A -->|Type B| C[Both faces smooth]
    A -->|Type C| D[One face keyed, one smooth]
    E[Water Quality] --> F[Fresh, clean, no deleterious matter]
    G[Marking] --> H[Standard Mark as per BIS]

For detailed dimensions and tolerances, refer to Clause 7 of IS 3115.

IS 3115 - Types of Blocks: Key Specifications & Dimensions

Types of Blocks (Clause 5.7)

• Type A: Both faces keyed for plastering.
• Type B: Both faces smooth; suitable for use without plastering/rendering.
• Type C: One face keyed, one face smooth.

Dimensions & Tolerances (Clause 7.1)

Measured as per Appendix A of IS 2185 (Part 1): 1979.

Material Specifications

• Water: Fresh, clean, free from acids, alkalis, salts, or deleterious matter.
• Coarse Aggregate (Clause 5.6):
  • Natural stone aggregate (IS 383:1970)
  • Broken brick aggregate (IS 3068:1986)
  • Cinder aggregate (IS 2686:1977)
  • Other proven quality aggregates allowed.

Quality Criteria

• Compressive Strength (Clause 9.2): No individual block < 80% of specified average.
• Drying Shrinkage (Clause 10): ≤ 0.1% (per IS 2185 Appendix E).
• Moisture Movement (Clause 11): ≤ 0.05% (per IS 2185 Appendix F).

Joint Types (Fig.1)

• Tongue & Grooved Joint
• Double Grooved Joint

flowchart LR
    A[Block Types] -->|Type A| B[Both faces keyed]
    A -->|Type B| C[Both faces smooth]
    A -->|Type C| D[One face keyed, one smooth]
    E[Dimensions] --> F[Length: 390 mm]
    E --> G[Width: 90,190,290 mm]
    E --> H[Height: 90,190 mm]

For detailed testing procedures, refer to IS 2185 (Part 1).

IS 3115: General Requirements Summary

• Rounding off values: Follow IS 2:1960 rules; retain significant figures as per specified values.

• Lot acceptance (Clause 12.4.1):

  • Max 2 blocks with dimensional defects or visual faults allowed in inspected sample.

• Moisture Movement (Clause 3.7):
  [ \text{Moisture Movement (%)} = \frac{L_{wet} - L_{dry}}{L_{dry}} \times 100 ]
  where (L_{dry}) = length after drying, (L_{wet}) = length after immersion.

• Block quality (Clause 4):

  • Blocks must be sound, crack-free, no broken edges or distortion.
  • Bedding surface perpendicular to block face.
  • Ends may be plain, tongued & grooved, or double grooved (see Fig.1 in the code).

• Drying shrinkage & moisture movement tests (Clause 12.4.3):

  • All test specimens must pass; if failed, test 3 more blocks—all must pass.

• Manufacturer's certificate (Clause 13):

  • Manufacturer must certify conformity to specification on request.

Key Table: Lot Acceptance Criteria (Clause 12.4.1)

flowchart TD
    A[Blocks Manufactured] --> B{Inspection}
    B -->|≤ 2 defects| C[Lot Accepted]
    B -->|> 2 defects| D[Lot Rejected]
    C --> E[Test Specimens for Shrinkage & Moisture Movement]
    E -->|All Pass| F[Conforms to IS 3115]
    E -->|Fail| G[Test 3 More Specimens]
    G -->|All Pass| F
    G -->|Fail| D

This ensures quality and dimensional compliance for masonry blocks per IS 3115.

IS 3115: Materials Key Points & References

IS 3115 primarily references Indian Standards for materials used in concrete blocks:

Important Specifications:

• Density & Compressive Strength: Mean values must meet minimum limits as per Clauses 8.1 and 9.1.
• Marking: Blocks may carry the BIS Standard Mark (Clause 14.2), ensuring quality compliance.
• Rounding Off: Test results must be rounded per IS 2:1960 rules for numerical values.

Summary:

Use materials conforming to the above IS codes to ensure compliance in block manufacturing. Check density and compressive strength against IS 3115 minimums.

flowchart TD
    A[Materials] --> B[Portland Cement (IS 269)]
    A --> C[Aggregates (IS 383)]
    A --> D[Concrete Blocks (IS 2185)]
    A --> E[Fly Ash (IS 3812)]
    A --> F[Lime & Pozzolana (IS 712, IS 4098)]
    B --> G[OPC, PPC, PSC]
    D --> H[Solid & Hollow Blocks]

For detailed material properties, refer to the respective IS codes listed.

IS 3115: Manufacture of Concrete Blocks – Key Points

1. Materials

• Water: Must be fresh, clean, free from acids, alkalis, salts, or deleterious substances (Clause 5.7).
• Refer to related IS standards for materials:
  • Cement: IS 269 (OPC), IS 455 (Portland slag cement), IS 1489 (PPC)
  • Aggregates: IS 383 (coarse and fine aggregates)
  • Pozzolanas and additives: IS 3812 (fly ash), IS 1344 (calcined clay pozzolana)

2. Block Types

• Type A: Both faces keyed for plastering.
• Type B: Both faces smooth, suitable for use without plaster.
• Type C: One face keyed, one face smooth.

3. Quality Control & Certification

• Manufacturer must ensure blocks conform to IS 3115 requirements.
• Upon request, a Manufacturer’s Certificate must be supplied (Clause 13).
• Testing includes drying shrinkage and moisture movement (Clause 12.4.3).

4. Marking

• Each block may be marked with the Standard Mark to indicate compliance (Clause 14.2).

5. Rounding Off

• Test results should be rounded off per IS 2:1960 rules, maintaining the same significant figures as specified.

Summary Table: Block Types

flowchart LR
    A[Raw Materials] --> B[Mixing & Molding]
    B --> C[Block Types: A, B, C]
    C --> D[Quality Control Tests]
    D --> E[Manufacturer's Certificate]
    E --> F[Marking with Standard Mark]

For detailed dimensional tolerances and manufacturing processes, refer to Clause 7 and related IS standards listed in Annex A.

IS 3115: Dimensions and Tolerances for Concrete Blocks

Key Dimensions (Clause 7.1 & Table 7.1)

• Sizes are measured per Appendix A of IS 2185 (Part 1): 1979.
• Blocks classified as Type A, B, C based on face finish (keyed or smooth).

Tolerances (Clause 12.4.1)

• In any inspected lot, not more than two blocks should exceed dimensional tolerance or have visual defects.
• Dimensional compliance is judged by rounding off values per IS 2:1960 rules.

Notes:

• Water used in manufacture must be fresh, clean, and free from deleterious substances (Clause 5.7).
• Blocks can be keyed for plastering or smooth for direct use.

Summary Table for Dimensions & Tolerances

flowchart TD
    A[Block Types] -->|Type A| B[Both faces keyed]
    A -->|Type B| C[Both faces smooth]
    A -->|Type C| D[One face keyed, one smooth]
    E[Dimensions] --> F[Length = 390 mm]
    E --> G[Width = 90,190,290 mm]
    E --> H[Height = 90,190 mm]
    I[Tolerances] --> J[Max 2 blocks outside limits per lot]
    I --> K[Round off per IS 2:1960]

This concise summary covers the essential dimensional and tolerance requirements from IS 3115.

IS 3115 - Block Density: Key Points

• Definition (Clause 3.5):
  Block Density = Mass of block / Overall volume (including holes, cavities, end recesses)

• Minimum Density (Clause 8):
  As per IS 2185 (Part 1), Appendix B, block density ≥ 1000 kg/m³

• Hollow Block Specifications (Clause 7.3):

  • Must have ≥ 1 cavity
  • Minimum wall thickness = 40 mm

• Compressive Strength (Clause 12.4.2):
  Mean block density and compressive strength must meet minimum limits (density ≥ 1000 kg/m³)

Summary Table:

Formula:

[ \text{Block Density} = \frac{\text{Mass of block (kg)}}{\text{Overall volume (m}^3\text{)}} ]

flowchart LR
    A[Block] --> B{Type}
    B -->|Solid| C[100% Solid]
    B -->|Hollow| D[Cavities ≥1]
    D --> E[Wall thickness ≥ 40 mm]
    A --> F[Mass]
    A --> G[Volume including cavities]
    F & G --> H[Calculate Density = Mass/Volume]
    H --> I{Density ≥ 1000 kg/m³?}
    I -->|Yes| J[Meets IS 3115]
    I -->|No| K[Reject]

This ensures compliance with IS 3115 block density and structural requirements.

IS 3115: Compressive Strength of Hollow Concrete Blocks

Key Specifications:

• Minimum average compressive strength: 3.5 MPa (Clause 9.1)
• Testing condition: Blocks saturated by immersion in water for 24 hours at room temperature.
• Area for calculation: Use gross cross-sectional area of the specimen.
• Individual block strength: Should not be less than 80% of the minimum average (i.e., not below 2.8 MPa) (Clause 9.2).
• Block wall thickness: Minimum 40 mm (Clause 7.3).
• Minimum block density: 1000 kg/m³ (Clause 8).

Testing Procedure Reference:

• Compressive strength test as per Appendix C of IS 2185 (Part 1): 1979.
• Drying shrinkage ≤ 0.1% (Appendix E).
• Moisture movement ≤ 0.05% (Appendix F).

Summary Table:

Formula for Compressive Strength:

[ f_c = \frac{P}{A} ]

• ( f_c ) = Compressive strength (MPa)
• ( P ) = Load at failure (N)
• ( A ) = Gross cross-sectional area (mm²)

flowchart TD
    A[Prepare 8 block specimens] --> B[Immerse in water for 24 hours]
    B --> C[Test compressive strength on saturated blocks]
    C --> D[Calculate average strength \(f_c = P/A\)]
    D --> E{Is average ≥ 3.5 MPa?}
    E -- Yes --> F

Drying Shrinkage - IS 3115 Key Points & Formulas

Definition (Clause 3.6):
Drying shrinkage =
[ \frac{L_{wet} - L_{dry}}{L_{dry}} \times 100% ]
where:

• (L_{wet}) = length after water immersion
• (L_{dry}) = length after drying to constant length

Specifications (Clauses 10 & 12.4.3)

• Drying shrinkage ≤ 0.1% (measured per IS 2185 Part 1, Appendix E)
• Test specimens must meet criteria in Clauses 10 & 11; if failed, retest 3 more blocks
• Manufacturer must certify conformity

Moisture Movement (Clause 3.7 & 11)

• Moisture movement =
  [ \frac{L_{dry} - L_{immersed}}{L_{dry}} \times 100% ]
• Limit ≤ 0.05% (per IS 2185 Part 1, Appendix F)

Additional Notes

• Specimens should be largest possible dimension from hollow blocks
• Blocks must be free from cracks and defects (Clause 4)
• Compressive strength tolerance: no block below 80% of specified average (Clause 9.2)

flowchart LR
    A[Prepare Specimen] --> B[Immerse in Water]
    B --> C[Measure Length \(L_{wet}\)]
    C --> D[Dry to Constant Length]
    D --> E[Measure Length \(L_{dry}\)]
    E --> F[Calculate Drying Shrinkage \(\frac{L_{wet} - L_{dry}}{L_{dry}} \times 100\%\)]
    F --> G{Shrinkage ≤ 0.1%?}
    G -- Yes --> H[Pass]
    G -- No --> I[Retest 3 Specimens]

This ensures dimensional stability and durability of concrete blocks per IS 3115.

IS 3115: Moisture Movement in Concrete Blocks

Definition (Clause 3.7)

• Moisture Movement (%) =
  [ \frac{L_{wet} - L_{dry}}{L_{dry}} \times 100 ] where,
  (L_{dry}) = Length after drying to constant length
  (L_{wet}) = Length after subsequent immersion in water

Testing (Clause 12.3.2 & 12.4.3)

• Out of 20 blocks:
  • 3 for density test
  • 8 for compressive strength
  • 3 for drying shrinkage & moisture movement
• If any specimen fails moisture movement or drying shrinkage test, test 3 more blocks. All must pass.

Drying Shrinkage (Clause 3.6)

• Drying Shrinkage (%) =
  [ \frac{L_{dry} - L_{wet}}{L_{dry}} \times 100 ] where,
  (L_{wet}) = Length after immersion in water
  (L_{dry}) = Length after drying to constant length

General Requirements

• Blocks must be free from cracks, distortion, and defects.
• Bedding surface at right angles to block face.
• Ends may be plain, tongued & grooved, or double grooved.

Summary Table: Moisture Movement & Drying Shrinkage

This ensures dimensional stability of blocks under moisture variations, critical for durability and structural integrity.

IS 3115: Sampling and Criteria for Conformity

Key Points from Clause 12.4 (Criteria for Conformity):

• Lot Acceptance:
  A lot is accepted if no more than 2 blocks inspected have:

  • Dimensions outside tolerance limits, and/or
  • Visual defects.

• Compressive Strength (Clause 9.2):
  No individual block should have compressive strength less than 80% of the specified average.

• Drying Shrinkage (Clause 10):
  Maximum drying shrinkage ≤ 0.1% (per IS 2185 Part 1 Appendix E).

• Moisture Movement (Clause 11):
  Maximum moisture movement on immersion ≤ 0.05% (per IS 2185 Part 1 Appendix F).

• Rounding Off (IS 2:1960):
  Final test values must be rounded off to the same decimal places as specified in the standard.

Summary Table for Conformity Criteria

flowchart TD
    A[Sample Blocks from Lot] --> B{Check Dimensions & Visual Defects}
    B -- ≤ 2 defective --> C[Accept Lot]
    B -- > 2 defective --> D[Reject Lot]
    C --> E{Check Compressive Strength}
    E -- All ≥ 80% specified avg --> F[Accept Lot]
    E -- Any < 80% --> D
    F --> G{Check Drying Shrinkage ≤ 0.1%}
    G -- Yes --> H{Check Moisture Movement ≤ 0.05%}
    G --

Manufacturer's Certificate (IS 3115 - Clause 13)

• The manufacturer must ensure blocks conform to IS 3115 requirements.
• Upon request, a certificate must be issued to the purchaser or representative confirming compliance.
• Certificates confirm blocks meet all specified tests including drying shrinkage and moisture movement (Clauses 10 & 11).
• Test results must be rounded per IS 2:1960 rules, matching significant digits of standard values.
• Blocks may carry the Standard Mark (Clause 14.2) indicating BIS certification and quality control under BIS supervision.

Key Points for Manufacturer's Certificate:

Reference Standards for Materials:

• Cement: IS 269, IS 455, IS 1489
• Aggregates: IS 383, IS 3068
• Fly ash & Pozzolana: IS 3812, IS 1344
• Masonry units: IS 2185 (Part 1)

flowchart TD
    A[Manufacturer] --> B[Ensures compliance to IS 3115]
    B --> C[Conduct tests (Drying shrinkage, moisture movement)]
    C --> D{Tests Passed?}
    D -- Yes --> E[Issue Manufacturer's Certificate]
    D -- No --> F[Retest 3 more blocks]
    F --> D
    E --> G[Blocks marked with Standard Mark (optional)]

This certificate assures quality and conformity under BIS supervision, enabling trust in block performance.

IS 3115: Marking of Concrete Blocks (Clause 14)

Key Marking Requirements (Clause 14.1 & 14.2):

• Each block must be clearly and permanently marked with:
  • Source of manufacture (manufacturer's identification)
  • Year of manufacture (if required)
• Blocks may also carry the BIS Standard Mark, indicating compliance with IS 3115 under BIS supervision.

Purpose of Marking

• Ensures traceability and quality assurance.
• Confirms conformity to IS standards.
• Marking is governed by the Bureau of Indian Standards Act, 1986.

Summary Table for Marking Information

Notes:

• Marking must be permanent and legible.
• Use IS 2:1960 for rounding off numerical values in test results.
• Refer to IS 3812:1981 for fly ash specifications if used.

flowchart TD
    A[Concrete Block] --> B{Marking}
    B --> C[Manufacturer's ID]
    B --> D[Year of Manufacture (optional)]
    B --> E[Standard Mark (optional)]
    E --> F[BIS Certification]

This ensures product traceability and quality compliance as per IS 3115.