Ordinary Portland Cement, 33 grade- specification

IS 269: Scope & Key Specifications for Ordinary Portland Cement (33 Grade)

This standard covers manufacture, chemical, and physical requirements.

Chemical Composition Limits (Table 2)

Performance Improvers (Clause 4.1.1, Table 1)

• Max total addition: 5% by mass (including 1% additives)
• Examples:

Important Formula for Lime Ratio

[ \text{Lime ratio} = \frac{\text{CaO} - 0.7 \times \text{SO}_3}{2.8 \times \text{SiO}_2 + 1.2 \times \text{Al}_2\text{O}_3 + 0.65 \

IS 269 - Key References: Formulas, Tables & Specifications

1. Performance Improvers (Clause 4.1.1, Table 1)

• Total addition limit: Max 5% if combined.

2. Chemical Requirements for OPC 33 Grade (Table 2)

3. Physical Requirements (Refer Table 3 in IS 269)

• Includes fineness, consistency, setting times, and strength parameters (not detailed here).

Important Formula for Lime Ratio:

[ \text{Lime Ratio} = \frac

IS 269 - Key Definitions & Specifications Summary

1. Performance Improvers (Clause 4.1.1 & Table 1)

• Max addition by mass: 5% total (including 1% additives).
• Individual max limits (all 5%): Fly ash, Granulated slag, Silica fume, Limestone, Rice husk ash, Metakaolin.
• Requirements per IS standards (e.g., Fly ash - IS 3812 Part 1).

2. Chemical Requirements for OPC 33 Grade (Table 2)

3. Additional Chemical Limits (Clause 9.4)

• SiO2 + Al2O3 ≥ 94%
• Loss on ignition ≤ 2%
• Total alkalis (Na2O equiv.) ≤ 1.5%
• Particles retained on 45 micron sieve ≤ 1.5%

Formula Highlight:

[ \text{Lime Ratio} = \frac{CaO - 0.7 \times SO_3}{2.8 \times SiO_2 + 1.2 \times Al_2O_3 + 0.65 \times Fe_2O_3} ]

Note: Definitions align with IS 4845 for cement terminology.

flowchart LR
    A[Performance Improvers] --> B[Max 5% Addition]
    B --> C[Fly Ash, Slag, Silica Fume, etc.]
    D[Chemical Requirements] --> E[Lime Ratio 

IS 269 - Manufacture of Cement: Key Specifications & Tables

1. Performance Improvers (Clause 4.1.1 & Table 1)

• Max addition by mass: 5% for each improver; total max of 5% if combined.
• Types & Requirements:

2. Physical Requirements for OPC 33 Grade (Table 3, Clause 8.2.5.4)

3. Alkali Content (Clause 8.2)

• Alkali (Na₂O) content should be < 0.6% for reactive aggregates.
• Manufacturer must provide alkali content certificate on request.

4. Important Notes

• Cement storage: Weather-tight, dry conditions to prevent deterioration (see IS 4082).
• False set correction and

IS 269: Chemical Requirements Summary

Key Chemical Requirements (Clause 94.0 & Table 2)

Performance Improvers (Max 5% addition)

IS 269: Physical Requirements for Ordinary Portland Cement (33 Grade)

Key Chemical Ratios (Table 2)

• Lime ratio formula:
  [ \frac{\text{CaO} - 0.7 \times \text{SO}_3}{2.8 \times \text{SiO}_2 + 1.2 \times \text{Al}_2\text{O}_3 + 0.65 \times \text{Fe}_2\text{O}_3} = 0.66 - 1.02 ]
• Alumina to iron oxide ratio ≥ 0.66
• Insoluble residue ≤ 5%
• Magnesia ≤ 6%
• Loss on ignition ≤ 5%
• Chloride content ≤ 0.1%
• Alkali content ≤ 0.05% (Na2O equivalent)

Notes:

• Cement must show progressive strength increase from 72 h.
• For reactive aggregates, use cement with alkali content < 0.6% Na2O (see IS 456 Clause 8.2.5.4).
• Storage: Weather-tight, dry conditions to prevent deterioration.

flowchart TD
    A[Ordinary Portland Cement] --> B[Fineness ≥ 225 m²/kg]
    A --> C[Soundness ≤ 

IS 269 - Sampling Key Points

• Sampling Method: As per Clause 11.2, sampling of cement must follow IS 3535:1986 (Methods of sampling hydraulic cement).

• Sample Size for Bagged Cement (Annex B):

• Sampling Procedure:

  • Bags must be selected randomly (see IS 4905 for random sampling methods).
  • Average net quantity per bag in sample ≥ 50 kg.

• Testing Timeline: Tests on samples should be conducted as soon as possible after sampling (Clause 12.2.3).

• Re-testing: Cement stored > 6 months in bulk or > 3 months in bags after testing must be retested before use (Clause 13.2).

Summary Flow of Sampling & Testing

flowchart TD
    A[Start: Cement Batch] --> B[Random Sampling as per IS 3535]
    B --> C[Sample Size as per Batch Size (Annex B)]
    C --> D[Carry out Tests ASAP (Clause 12.2.3)]
    D --> E{Pass Tests?}
    E -->|Yes| F[Use Cement]
    E -->|No| G[Reject Cement]
    F --> H[Monitor Storage Time]
    H --> I{Storage > 3/6 months?}
    I -->|Yes| J[Retest Cement]
    I -->|No| K[Continue Use]

References:

• IS 3535:1986 — Sampling of Hydraulic Cement
• IS 4905:1968 — Methods for Random Sampling
• IS 269:2015 — Cement Specification (Clause 11.2, 12.2.3, 13.2, Annex B)

This ensures representative, reliable sampling and testing for cement quality control.

Manufacturer's Certificate - IS 269 Key Points

Clause 8.1:

• Manufacturer must certify cement conforms to IS 269 standards.
• Certificate includes test results within 10 days (except 28-day compressive strength).
• Must specify type & % of performance improvers used.

Clause 8.2:

• If requested, certificate must indicate alkali content (Na2O equivalent).
• Recommended alkali content ≤ 0.6% Na2O for reactive aggregates (see IS 456 Clause 8.2.5.4).

Key Physical Requirements (Table 3 - OPC 33 Grade)

Additional Notes

• Cement should be stored in weather-tight conditions (IS 4082).
• For reactive aggregates, use low alkali cement or alternative measures (IS 456).
• Certificate must also include chemical limits like SiO2, Al2O3, Fe2O3 ratios, MgO, loss on ignition, chloride content (see Clause 2.8).

flowchart TD
    A[Manufacturer] --> B[Tests cement as per IS 269]
    B --> C{Request for Alkali Content?}
    C -- Yes --> D[Include Alkali Content in Certificate]
    C -- No --> E[Standard Certificate]
    D --> F[Send Certificate to Purchaser within 10 days]
    E --> F

Summary: Manufacturer's certificate must confirm compliance with IS 269 physical and chemical specs

IS 269: Packing and Marking Key Points

• Packing Material: As per Clause 9.4.3, packing material is mutually agreed between manufacturer and purchaser.

• Packing Types (Clause 9.4):

  • Cement can be packed in bags or drums.
  • Net quantity per bag/drum is agreed upon between parties.
  • Common net weights: 25 kg, 50 kg (standard practice).

• Marking Requirements (Clause 9.4.2):

  • Each bag/drum must be marked with:
    • The words "FOR EXPORT"
    • The net quantity of cement
  • Marking must be in indelible ink for durability.

• Delivery Advice (Clause 10.2):

  • Shipment documents must include packing details.
  • Information on bags/drums must match delivery advice.

Typical Packing Marking Example:

This ensures traceability, quality, and compliance for export cement shipments.

Delivery and Documentation per IS 269

1. Delivery Advice & Documentation (Clause 10.2):

• Delivery advices must accompany shipments (packed or bulk cement).
• Cement drums must also carry similar information (see Clause 9.3).
• Documentation ensures traceability and quality verification.

2. Sampling & Testing (Clause 11.1.1):

• Samples must be taken within 3 weeks of delivery.
• Testing must begin within 1 week of sampling.

3. Storage & Retesting (Clause 13.2):

• Cement stored in bulk >6 months or in bags >3 months after testing must be retested before use.
• Reject if it fails any standard requirements.

4. Packing & Quantity Tolerance (Annex B):

• Average net quantity per bag ≥ 50 kg.
• Sample size depends on batch size (see table below):

5. Reference Standards for Packaging & Testing:

• IS 4905: Random sampling methods.
• IS 2580, IS 11761, IS 12089: Specifications for jute, HDPE, and paper sacks.
• IS 4031 (Parts 2,3,5,6,8): Physical tests for cement (fineness, soundness, setting time, strength).

flowchart TD
    A[Shipment of Cement] --> B[Delivery Advice]
    B --> C[Sampling within 3 weeks]
    C --> D[Testing within 1 week]
    D --> E{Storage Duration}
    E -- >6 months bulk or >3 months bags --> F[Retesting]
    F --> G{Pass?}
    G -- Yes --> H[Use Cement]
    G -- No --> I[Reject Cement]

This ensures cement quality and compliance from dispatch to site use.

Sampling and Testing Procedures - IS 269 Key Points

Sampling (Clause 11.2)

• Sampling must follow IS 3535: "Methods of sampling hydraulic cement."
• Bags for sampling are selected randomly per IS 4905.
• Sample size depends on batch size (Annex B):

Testing (Clause 12.2.3)

• Tests must be performed promptly after sampling.
• Refer to IS 4031 series for physical tests:
  • Fineness (Part 2)
  • Soundness (Part 3)
  • Setting times (Part 5)
  • Compressive strength (Part 6)
  • Transverse strength (Part 8, optional)

Rejection Criteria (Clause 13.2)

• Cement stored >6 months in bulk or >3 months in bags after testing must be retested.
• Reject if fails to meet IS 269 requirements.

Physical Requirements for OPC 33 Grade (Table 3)

Summary Flow of Sampling & Testing

flowchart TD
    A[Start: Cement Batch] --> B[Random Sampling per IS 3535 & IS 4905]
    B

IS 269: Testing and Independent Verification Key Points

1. Independent Testing (Clause 12.2)

• Sample Collection: Before or immediately after delivery, as per purchaser's option.
• Testing Standard: Tests must follow IS 269 procedures under purchaser's written instructions.

2. Physical Requirements (Clause 8.2.5.4 & Table 3)

• Alkali Content: For reactive aggregates, cement alkali (Na₂O) < 0.6% recommended (see IS 456 Clause 8.2.5.4).

3. Retesting & Rejection (Clause 13.2)

• Cement stored >6 months in bulk or >3 months in bags after testing must be retested.
• Reject if fails to meet IS 269 requirements.

4. Sampling & Packaging (Annex B)

• Sample size depends on batch size (e.g., 20 bags for 100-150 batch).
• Random sampling per IS 4905.

flowchart TD
    A[Sample Collection] --> B{Timing}
    B -->|Before Delivery| C[Test as per IS 269]
    B -->|After Delivery| C
    C --> D[Physical Tests: Fineness, Soundness, Setting Time, Strength]
    D --> E{Pass?}
    E -->|Yes| F[Accept Cement]
    E -->|No| G[Retest or Reject]

References: IS 4031 (Parts 2,3,5,6), IS 456 (alkali content), IS 4905 (sampling).

Rejection of Cement as per IS 269: Key Points & Criteria

Clause 13.1 & 13.2: Rejection Conditions

• Cement shall be rejected if it does not meet any standard requirements.
• Cement stored in bulk > 6 months or in bags > 3 months after testing must be retested before use.
• Failure to meet any test criteria leads to rejection.

Chemical & Physical Requirements (Summary)

Sampling & Storage

• Random sampling as per IS 4905.
• Storage in weather-tight, dry conditions (see IS 4082).
• Bags must comply with IS 2580, IS 11761, IS 12089 for packing.

Summary Table: Rejection Criteria

flowchart TD
    A[Cement Storage] --> B{Storage Duration}
    B -->|Bulk > 6 months| C[Retest Required]
    B -->|Bags > 3 months| C
    B -->|Within limits| D[Use Without Retest]
    C --> E{Test Results}

IS 269: List of Referenced Indian Standards (Annex A)

This standard references multiple IS codes essential for cement specification, testing, and packaging:

Key Notes:

• Sampling and testing methods are standardized (see IS 3535, IS 4031 series).
• Packaging specifications ensure cement quality during storage and transport (IS 11652, IS 11761, IS 12154).
• Pozzolanic materials and supplementary cementitious materials have dedicated standards (IS 1727, IS 3812).
• Definitions and terminology are standardized in IS 4845.
• Random sampling methods per IS 4905 ensure representative testing.

Sampling Size Table (Annex B):

| Batch Size (bags) | Sample Size (bags) | |-------------------

Tolerance Requirements for Quantity of Cement Packed in Bags (IS 269)

• Net Quantity per Bag:

  • Standard: 50 kg (Clause 9.1.1)
  • Alternatives: 25, 10, 5, 2, or 1 kg as agreed (Clause 9.2)

• Tolerance on Quantity:

  • As per Standards of Weights and Measures (Packaged Commodities) Rules, 1977 and Annex B of IS 269 (Clause 1.2 & 9.4.4)
  • The net quantity must be equal to or more than the specified quantity (Clause 9.4.4)

Typical Tolerance Limits (from Annex B & Packaged Commodities Rules)

Summary:

• Minimum cement quantity per bag must not be less than the nominal weight.
• Positive tolerance allows slight overfilling; negative tolerance is strictly limited.
• Exact tolerances are governed by national packaging rules and IS 269 Annex B.

flowchart LR
    A[Specified Net Weight] --> B{Tolerance Check}
    B -->|Within Tolerance| C[Acceptable]
    B -->|Below Minimum| D[Reject: Underweight]
    B -->|Above Max| E[Acceptable: Overfilled]

This ensures bags meet quality and legal packaging standards.