Portland Slag Cement – Specification

IS 455: Scope and Related Specifications

• Scope (Clause 2.1):
  IS 455 covers specifications for Ordinary Portland Cement (OPC) 33 grade, including its physical and chemical properties, testing methods, and packaging.

• Key Adjunct Indian Standards (Annex A):
  These standards complement IS 455 for cement quality, sampling, testing, and packaging:

• Definitions:
  Use IS 4845:1968 for cement-related terminology.

Summary Table: Cement Grade & Packaging

This scope ensures uniformity in cement quality, testing, and packaging, critical for structural safety and durability.

IS 455 - Referenced Indian Standards (Clause 2.1)

IS 455 refers to various Indian Standards essential for cement specification, testing, packing, and terminology. Key referenced IS codes include:

Additional Notes:

• IS 12089, 12154, 12174 (1987) cover granulated slag for Portland cement manufacture.
• IS 4031 (Parts 1-13) detail physical testing methods for hydraulic cement.

These standards ensure uniformity in cement quality, sampling, packaging, and testing procedures, forming a comprehensive framework for cement manufacturing and usage under IS 455.

IS 455: Definitions - Key Points

• Clause 3.1 refers to IS 4845:1968 for definitions and terminology related to hydraulic cement.
• IS 4845 provides standardized terms such as:
  • Hydraulic Cement: Cement that sets and hardens by chemical reaction with water.
  • Ordinary Portland Cement (OPC): Cement conforming to IS 269.
  • Grade: Strength classification, e.g., 33, 43, 53 grade OPC.
• IS 455 relies on these definitions for consistency in specifications and testing.

Important Related Standards (Clause 2.1):

Summary:

• Use IS 4845:1968 for all cement-related definitions.
• IS 455 specifies grades and properties based on these definitions.
• Refer to IS 269 for cement grade specifications.

graph LR
A[IS 455] --> B[Definitions per IS 4845]
B --> C[Hydraulic Cement]
B --> D[Ordinary Portland Cement]
B --> E[Grades of Cement (33, 43, 53)]
A --> F[Specifications per IS 269]

This ensures uniform terminology and clarity in cement standards.

IS 455: Manufacture of Ordinary Portland Cement (OPC) – Key Points

1. Manufacture Specifications

• Cement manufacture must comply with IS 269:1989 for 33 grade OPC.
• Packing materials (HDPE, PP, jute, multi-wall paper sacks) follow IS 11652, 11653, 2580, 11761 respectively.
• Sampling and testing methods per IS 3535, 4032, 4905 ensure quality control.

2. Packing and Sampling (Clause 9.2 & 9.2.2.3)

• Packing material is agreed upon between manufacturer and purchaser.
• Average net mass per bag: ≥ 50 kg.
• Sample size depends on batch size:

• Bags are randomly selected as per IS 4905:1968.

3. Quality Control

• Chemical and physical tests per IS 4032 and IS 4031 (Parts 1-13).
• Tolerances and definitions as per IS 4845.

Summary Diagram: Manufacture & Packing Process

flowchart TD
    A[Raw Materials] --> B[Manufacturing Plant]
    B --> C[Quality Testing (IS 4031, 4032)]
    C --> D[Packing (HDPE/PP/Jute/ Paper bags)]
    D --> E[Sampling (IS 4905) based on Batch Size]
    E --> F[Dispatch to Purchaser]

Note: For detailed chemical composition, physical properties, and testing procedures, refer to IS 269 and IS 4031 series.

IS 455 - Chemical Requirements for Portland Slag Cement (Clause 5.2)

Additional Specifications:

• Total chloride content:
  • ≤ 0.05% by mass for prestressed and long-span reinforced concrete.
  • For other concrete types, limits are subject to mutual agreement.
• Manufacturing:
  • Cement made by intergrinding Portland cement clinker, granulated slag (25%-65%), gypsum (natural or chemical).
  • Only gypsum, water, and ≤1% air-entraining agents allowed as additives.
• Testing Standards:
  • Chemical tests as per IS 4032:1985.
  • Chloride content test as per IS 12423:1988.
  • Granulated slag as per IS 12089:1987.

This ensures durability and performance in concrete structures by controlling harmful chemical constituents.

IS 455 - Physical Requirements Summary

1. Testing Temperature (Clause 11.2)

• Physical tests should be conducted at 27 ± 2°C.
• Actual temperature during testing must be recorded.

2. Chemical Limits for Portland Slag Cement (Clause 5.2, Table 5)

• Chloride content: Max 0.05% for prestressed/long span RC structures (IS 12423:1988).

3. Packaging Tolerances (Annex B, Clause 9.2)

• Average net mass per bag ≥ 50 kg.
• Sample sizes based on batch size (e.g., 100–150 bags → 20 sample bags).

This ensures cement quality and consistency for structural safety.

IS 455: Storage and Identification of Cement — Key Points

• Storage (Clause 7.1):

  • Cement must be stored in a weather-tight building to prevent moisture ingress.
  • Storage should allow easy access for inspection and identification.
  • Avoid direct contact with the ground; use pallets or platforms.
  • Maintain proper ventilation to minimize deterioration.

• Sample Storage (Clause 10.1.2):

  • If testing cannot be done within 1 week, samples must be stored in airtight containers to preserve quality.

• Sampling & Identification (Clause 10.3):

  • Manufacturer/supplier must provide facilities, labor, and materials for sampling, packing, and identification of cement batches.

Summary Table: Cement Storage Requirements

flowchart TD
    A[Receive Cement] --> B[Store in Weather-tight Building]
    B --> C[Easy Access for Inspection]
    B --> D[Protect from Dampness]
    C --> E[Sampling by Manufacturer]
    E --> F[Pack Samples in Airtight Containers if Delay > 1 Week]
    F --> G[Testing]

Note: Proper storage and identification ensure cement quality and compliance with IS 455.

IS 455 Manufacturer's Certification: Key Points

• Clause 8.1:
  The manufacturer must ensure the cement meets IS 455 requirements and, if requested, provide a certificate of conformity to the purchaser within 10 days of dispatch.

• Clause 8.2:
  The manufacturer must also provide a certificate indicating the total chloride content (% by mass) within 10 days of dispatch.

Important Specifications:

Summary Diagram:

flowchart TD
    A[Cement Manufacturing] --> B[Quality Checks]
    B --> C{Meets IS 455?}
    C -->|Yes| D[Prepare Certification]
    D --> E[Send Certificate to Purchaser<br>within 10 days]
    C -->|No| F[Reject/Rectify Cement]

Note: Certification ensures traceability and quality assurance as per IS 455 standards.

IS 455 - Packing and Marking of Cement: Key Points

• Packing Material:
  As per Clause 9.2.2.3, the packing material must be mutually agreed upon by the manufacturer and purchaser. No fixed material is prescribed in the code.

• Packing for Export:
  According to Clause 9.2.2, when cement is for export, packing can be in:

  • Bags or
  • Drums
    The average net mass per bag/drum is also to be agreed upon between the purchaser and manufacturer.

• Typical Packing Mass:
  While IS 455 does not specify exact weights, common practice includes:

  • 50 kg bags (standard)
  • Drums vary, often 25 kg to 50 kg depending on export requirements.

• Marking:
  Marking details (manufacturer, grade, weight, batch no.) should be clearly visible on each bag or drum as per purchaser's requirements.

Summary Table (Typical Practice)

flowchart LR
    A[Manufacturer] -->|Agrees on packing material & mass| B[Purchaser]
    B --> C{Packing Type}
    C --> D[Bags (e.g., 50 kg)]
    C --> E[Drums (e.g., 25-50 kg)]
    D --> F[Marking as per agreement]
    E --> F

Note: Always confirm packing and marking details contractually to avoid disputes.

IS 455 Sampling Key Points

• Sampling Method:
  Sampling must follow IS 3535:1986 procedures (Clause 10.2).

• Who Can Sample:
  Samples can be taken by the purchaser, their representative, or the superintendent’s representative (Clause 10.1).

• Sample Size for Cement Bags:
  Sampling size depends on batch size (Annex B, Clause 9.2):

• Mass Requirement:
  Average net mass per bag in the sample should be ≥ 50 kg.

• Random Selection:
  Bags must be selected randomly as per IS 4905:1968.

• Manufacturer’s Role:
  Must provide facilities, labor, materials for sampling, packing, and identification (Clause 10.3).

flowchart TD
    A[Batch of Cement Bags] --> B[Random Selection per IS 4905]
    B --> C[Sample Size per Batch Size Table]
    C --> D[Sampling & Packing per IS 3535]
    D --> E[Testing & Identification]

This ensures representative sampling for reliable quality control.

IS 455: Key Testing Specifications & Formulas

1. Testing Temperature (Clause 11.2)

• Physical tests on cement should be performed at 27 ± 2°C.
• Actual temperature during testing must be recorded.

2. Independent Testing (Clause 11.4)

• Testing should be conducted independently to ensure unbiased results.

3. Sampling & Tolerance for Cement Bags (Annex B, Clause 9.2)

• Samples must be randomly selected (refer IS 4905:1968).

4. Referenced Standards for Testing

• IS 269: Ordinary Portland Cement specification
• IS 650: Standard sand for testing cement
• IS 4031 (Parts 1-13): Methods of physical tests for hydraulic cement
• IS 4032: Chemical analysis of hydraulic cement
• IS 4905: Random sampling methods

Summary Diagram: Testing Process Flow

flowchart TD
    A[Sample Collection] --> B[Temperature Control (27 ± 2°C)]
    B --> C[Physical & Chemical Tests]
    C --> D[Independent Testing]
    D --> E[Result Recording & Reporting]

Note: For detailed test methods and formulas (e.g., fineness, consistency, setting time), refer to IS 4031 series.

IS 455: Rejection Criteria for Cement

Key Points:

• Clause 12.1: Cement is rejected if it fails any specified requirement in the standard (strength, fineness, soundness, etc.).

• Sampling (Clause 10.2 & 11.4):

  • Sampling must follow IS 3535:1986.
  • Independent testing is recommended to verify compliance.

• Mass Tolerance for Cement Bags (Annex B, Clause 9.2):

• Average net mass of sampled bags must be ≥ 50 kg.

Summary:

• Cement failing any test (strength, setting time, fineness, soundness) is rejected.
• Use random sampling per IS 4905:1968.
• Check mass tolerance with sample sizes above.
• Follow IS 3535:1986 for sampling procedures.

flowchart TD
    A[Cement Batch] --> B[Sampling per IS 3535]
    B --> C{Tests per IS 455}
    C -->|Pass| D[Accept Cement]
    C -->|Fail| E[Reject Cement]
    B --> F[Mass Tolerance Check (Annex B)]
    F -->|Pass| C
    F -->|Fail| E

This ensures quality control and compliance with IS 455 standards.

IS 455: List of Referenced Standards (Clause 2.1)

IS 455 references several Indian Standards essential for cement and concrete specifications:

Key Notes:

• These standards cover cement grading, sampling, testing, packing, and terminology.
• Definitions in IS 4845:1968 apply to IS 455.
• Sampling and testing methods ensure quality control.
• Packaging standards ensure proper handling and storage.

This list is crucial for compliance and quality assurance in cement and concrete production.

Tolerance Requirements for Mass of Cement Packed in Bags (IS 455:1989)

• Average Net Mass: For 50 kg bags, the average net mass in a sample must be ≥ 50 kg.
• Sample Size Based on Batch Size:

• Tolerance Limits: As per clause 9.2.1.1 (not fully provided here), tolerances apply to individual bag masses around the nominal weight.
• Smaller Bags: For 25 kg bags, average net mass must be ≥ 25 kg with similar tolerances.
• Sampling: Bags must be randomly selected per IS 4905:1968.

Summary:

• The average net mass of cement bags in a sample must not be less than the nominal weight (25 or 50 kg).
• The sample size depends on the batch size.
• Individual bag weights must lie within specified tolerances (refer IS 455 clause 9.2.1.1).

This ensures quality control and uniformity in cement packaging.

Composition of Technical Committee (Annex C, IS 455)

The Technical Committee for IS 455 (Portland Slag Cement) formulation includes experts from diverse organizations:

• Includes chief engineers, directors, research officers, and industry experts.
• Alternates are nominated for most members.
• Represents government, research institutions, cement manufacturers, and infrastructure bodies.

This diverse composition ensures comprehensive technical inputs for cement standards.

For detailed names and affiliations, see Annex C of IS 455.