Pulverized fuel ash for lime-pozzolana mixture applications.

IS 15648: Scope & Key Specifications for Pulverized Fuel Ash (PFA)

Scope

• Covers siliceous and calcareous pulverized fuel ash (PFA) used in cement and concrete.
• Definitions per IS 4305 apply.
• Referenced standards in Annex A are integral to this standard.

Chemical Requirements (Table 1, Clause 7.1)

Physical Requirements (Table 2, Clauses 8 & 12.1)

Delivery (Clause 11.1)

• PFA supplied in bulk or bags (15, 30, 40, 300, 600, 800 kg) as agreed.
• Bags must show net mass and supplier's identification.
• Mass tolerance mutually agreed.

This standard ensures quality control of PFA for concrete use, specifying chemical & physical criteria and delivery norms.

IS 15648 - References Summary

Annex A lists Indian Standards referenced by IS 15648, which form integral provisions. Key standards include:

Important Notes:

• Rounding off of test results follows IS 2:1960 rules.
• Net mass and bag color coding for pulverized fuel ash (PFA) are specified.
• Testing samples should be conducted promptly (Clause 14.3.2).
• Always refer to the latest editions of these standards for up-to-date provisions.

Quick Reference: Rounding off (IS 2:1960)

This ensures uniformity and accuracy in test reporting and material specifications in line with IS 15648.

IS 15648 - Terminology & Key Specifications

• Mound Ash (Clause 3.8):
  Fly ash and/or bottom ash mixed in any proportion, conveyed and deposited in dry form.

• Pulverized Fuel Ash Grades:

  Grade	Use Case
  Grade 1	Lime-based air/water cured and steam cured products (at atmospheric pressure)
  Grade 2	Lime-based autoclaved products

• Note: Grade 1 ash can substitute Grade 2.

• Reference Standards: Definitions per IS 4305; consult Annex A for related standards and updates.

This terminology helps classify ash types for appropriate use in lime-based construction products, ensuring compatibility with curing methods.

flowchart LR
    A[Mound Ash] -->|Mix| B[Fly Ash]
    A -->|Mix| C[Bottom Ash]
    D[Pulverized Fuel Ash] -->|Grade 1| E[Lime-based air/water & steam cured]
    D -->|Grade 2| F[Lime-based autoclaved]
    E -->|Note| F

IS 15648: Classification of Pulverized Fuel Ash (PFA)

Classification Based on Lime Content

• Siliceous Pulverized Fuel Ash: Low lime content.
• Calcareous Pulverized Fuel Ash: Higher lime content.

Grades of PFA

Key Chemical Requirements (Table 1, Clause 7.1)

Physical Requirements (Table 2, Clauses 8 & 12.1)

IS 15648: Extraction & Specifications of Pulverized Fuel Ash (PFA)

Key Points on Extraction & Grades

• Extraction: PFA is extracted as dry fly ash or bottom ash or their mixture (called Mound Ash).
• Grades:
  • Grade 1: For lime-based air/water cured and steam cured (at atmospheric pressure) products.
  • Grade 2: For lime-based autoclaved products.
  • Note: Grade 1 can substitute Grade 2.

Chemical Requirements (Table 1 Summary)

Testing

• Tests must be done on as-supplied PFA.
• If beneficiation or processing is done, tests are done post-processing.

Extraction Process (Simplified Flow)

flowchart LR
    A[Coal Combustion] --> B[Fly Ash + Bottom Ash]
    B --> C{Dry Collection}
    C -->|Collected as Dry Ash| D[Mound Ash]
    D --> E[Pulverized Fuel Ash (PFA)]

Summary:

• Extracted dry ash (fly/bottom/mixed) is tested chemically.
• Two grades defined by curing method.
• Chemical limits ensure suitability for lime-based products.
• Testing post any beneficiation is mandatory.

For detailed chemical limits and test methods, refer to Clause 7.1 & 14.2 of IS 15648.

IS 15648: Beneficiation, Segregation and Processing of Pulverized Fuel Ash (PFA)

Key Points from IS 15648:

• Purpose: Improve PFA properties like lime reactivity, loss on ignition (LOI), particle size, and chemical characteristics.
• Technologies Include:
  • Burning/removal of unburned carbon to reduce LOI.
  • Sieving/grading for controlling fineness and particle size distribution.
  • Grinding/attrition to reduce particle size further.
  • Thermal treatment to modify chemical properties.
  • Blending different qualities of fly ash to achieve desired standards.

Specifications & Chemical Requirements (Clause 7):

• PFA must meet chemical limits (e.g., silica, alumina, lime content).
• If raw PFA fails to meet standards, beneficiation/processing is mandatory.

Typical Beneficiation Effects:

Summary Diagram:

flowchart LR
    Raw_PFA -->|Beneficiation| Carbon_Removal
    Raw_PFA -->|Segregation| Sieving_Grading
    Raw_PFA -->|Processing| Grinding_Attrition
    Carbon_Removal --> Improved_LOI
    Sieving_Grading --> Improved_Fineness
    Grinding_Attrition --> Reduced_Particle_Size
    Thermal_Treatment --> Enhanced_Chemical_Properties
    Blending --> Consistent_Quality

Note: IS 15648 does not provide explicit formulas but emphasizes process routes and chemical limits for quality control. For detailed chemical limits and physical requirements, refer to Clause 7 and related tables in the standard.

IS 15648: Chemical Requirements for Pulverized Fuel Ash (PFA)

Key Chemical Specifications (Table 1, Clause 7.1)

Notes:

• Reactive Silica is critical for pozzolanic activity.
• Total Chlorides limited to 0.05% to ensure durability.
• Tests refer to standard IS methods for consistency.
• Chemical composition impacts strength, durability, and compatibility with cement.

Summary Diagram: Chemical Composition Limits for PFA

graph TD
    A[Pulverized Fuel Ash] --> B[Siliceous PFA]
    A --> C[Calcareous PFA]
    B --> D[SiO2 + Al2O3 + Fe2O3 ≥ 70%]
    B --> E[Reactive Silica ≥ 20%]
    B --> F[MgO ≤ 5%]
    B --> G[SO3 ≤ 5%]
    B --> H[Na2O ≤ 2.5%]
    B --> I[Chlorides ≤ 0

IS 15648: Physical Requirements for Pulverized Fuel Ash (PFA)

Key Specifications (Table 2, Clauses 8 & 12.1)

Important Notes:

• Fineness is measured by Blaine’s permeability method (IS 1727).
• Particle size distribution is determined by wet sieving using a 45-micron IS sieve.
• Lime reactivity is tested by compressive strength, indicating pozzolanic activity.
• Tests are conducted on oven-dried samples.
• Storage recommendations follow IS 4082 (for cement).

Summary Diagram of Physical Requirements

graph TD
    A[Pulverized Fuel Ash] --> B[Fineness ≥ 200-250 m²/kg]
    A --> C[Particles ≤ 40-45% retained on 45 µm sieve]
    A --> D[Lime Reactivity ≥ 3.0-3.5 N/mm²]

This ensures PFA quality for use as a pozzolanic material in concrete.

IS 15648: Moisture Content & Related Specifications for Pulverized Fuel Ash

1. Moisture Content Limits (Clause 7.2)

• Moisture content of pulverized fuel ash (PFA) must be controlled to ensure quality.
• Typical maximum moisture content for PFA is around 3-5% by weight (commonly specified in standards).
• Excess moisture adversely affects handling, packing, and performance in cementitious products.

2. Pulverized Fuel Ash Grades (Clause 3.8 & Table 3)

• Note: Grade 1 can substitute Grade 2.

3. Tolerance on Packed Mass (Clause 11.2.3)

• For 5 to 25 tonne loads, net mass tolerance = 0 to +0.5%.
• Ensures accurate packing and supply consistency.

Summary Table: Moisture & Packing Tolerance

flowchart LR
    A[Pulverized Fuel Ash] --> B{Grade}
    B --> C[Grade 1: Lime-based air/water & steam cured]
    B --> D[Grade 2: Lime-based autoclaved]
    A --> E[Moisture Content ≤ 5%]
    A --> F[Packed Mass Tolerance: 0 to +0.5% for 5-25t loads]

Ensure moisture control and correct grade selection for optimal product performance.

IS 15648: Manufacturer's Certificate & Marking Key Points

Manufacturer's Certificate (Clause 10)

• Supplier/manufacturer must ensure compliance of pulverized fuel ash (PFA) with IS 15648.
• Upon agreement, a certificate of conformity is issued to the purchaser or representative.

Marking Requirements (Clause 12.1)

Each bag/consignment must be clearly and permanently marked with:

• Manufacturer's identification
• Type of PFA: Siliceous or Calcareous
• Form & minimum fineness (refer Table 2)
• Batch/Control unit number
• Month and year of packing
• Any purchaser-required identification

Key Tables Summary:

flowchart TD
    A[Manufacturer] --> B{Confirm PFA meets IS 15648}
    B -->|Yes| C[Issue Manufacturer's Certificate]
    C --> D[Mark Bags with Required Info]
    D --> E[Supply to Purchaser]

Summary: Manufacturer certifies PFA quality per IS 15648, marks consignments with detailed info, ensuring traceability and compliance.

IS 15648 - Delivery of Pulverized Fuel Ash (PFA)

Key Specifications (Clause 11.1 & 11.2.3)

• Supply forms: Bulk or bags (jute, jute-laminated, paper, polyethylene-lined).
• Bag weights: Commonly 15, 30, 40, 300, 600, 800 kg (mutually agreed).
• Marking on bags: Net mass, supplier's name/trademark.
• Tolerance on bag mass: As agreed between purchaser and supplier.
• Tolerance on wagon/truck load (5–25 tonnes): Net mass tolerance of 0 to +0.5%.

Chemical Requirements (Table 1, Clause 7.1)

Physical Requirements (Table 2, Clauses 8 & 12.1)

Summary Diagram: Delivery Tolerance & Packaging

flowchart TD
    A[Pulverized Fuel Ash Delivery] --> B{Form}
    B --> C[

IS 15648: Marking and Packaging of Pulverized Fuel Ash

Key Specifications (Clause 12.1)

Each bag/consignment must be clearly and permanently marked with:

• Manufacturer identification
• Type of pulverized fuel ash (Siliceous or Calcareous)
• Form and minimum fineness (see Table 2 below)
• Batch/Control unit number
• Month and year of packing
• Any purchaser-required identification
• Optional: BIS Standard Mark (Clause 12.2)

Packaging (Clause 11.1)

• Supply in bulk or bags (jute, laminated paper, polyethylene-lined)
• Bag weights: 15, 30, 40, 300, 600, 800 kg (as agreed)
• Bags to bear net mass, supplier's name/trademark
• Mass tolerance mutually agreed

Table 2: Physical Requirements for Pulverized Fuel Ash

Summary Diagram: Marking & Packaging Flow

flowchart TD
    A[Pulverized Fuel Ash Production] --> B[Batching & Quality Check]
    B --> C[Packaging in Bags or Bulk]
    C --> D[Marking on Bags]
    D --> E[Dispatch to Purchaser]
    E --> F[Use in Construction]
    
    D -->|Marking Details| G[Manufacturer, Type, Fineness, Batch No., Date, BIS Mark]
    C -->|Bag Types| H[Jute, Paper, Polyethylene-lined]

Note: Refer to the Standards of Weights and Measures (Packaged Commodities) Rules, 1977 for detailed legal requirements.

Sampling in IS 15648: Key Points & Specifications

1. Sampling Method:

• Sampling shall follow IS 6491: Methods of sampling fly ash (Clause 13.2).
• Samples must be representative of the batch.

2. Facilities for Sampling (Clause 13.3):

• Supplier must provide all labor, materials, and facilities for sampling and packing.
• Samples must be properly identified for traceability.

3. Sample Testing (Clause 14.3.2):

• Tests on samples must be done as quickly as possible after sampling.

4. Packing & Mass Tolerance (Clause 11.2.1):

• Net mass per bag should be ≥ 15, 30, 40, 300, 600, or 800 kg as applicable.
• Number of bags sampled depends on batch size:

• Bags selected randomly per IS 4905 (Methods for random sampling).

Summary Diagram: Sampling Process Flow

flowchart TD
    A[Batch of Pulverized Fuel Ash] --> B[Random Selection of Bags (IS 4905)]
    B --> C[Sample Size as per Batch Size Table]
    C --> D[Sampling & Packing (Supplier's Responsibility)]
    D --> E[Identification & Labeling]
    E --> F[Testing (As per IS 6491 & Clause 14.3.2)]

References for Sampling:

• IS 6491: Sampling fly ash procedures
• IS 4905: Random sampling methods
• IS 2: Rounding off numerical test results

This ensures representative sampling, proper traceability, and quality control of pulverized fuel ash as per IS 15648.

IS 15648 - Testing: Key Points & References

Clause 14.3 - Independent Testing:

• Testing must be done on a representative sample drawn as per IS 6491.
• Tests should be carried out expeditiously after sampling (Clause 14.3.2).

Key References for Testing Procedures:

Important Notes:

• Sampling must follow IS 6491 to ensure representativeness.
• Final test values should be rounded off as per IS 2:1960.
• Net mass and packaging colors for pulverized fuel ash are standardized for easy identification.

Summary Flow for Testing Procedure:

flowchart TD
    A[Draw Representative Sample] --> B[Conduct Tests Expeditiously]
    B --> C[Analyze Results per Relevant IS Standards]
    C --> D[Round Off Results as per IS 2:1960]
    D --> E[Decide Compliance with Standard]

For detailed test methods, consult the referenced IS codes above.

IS 15648: List of Referenced Indian Standards

Key referenced IS codes in IS 15648 relate to testing and specifications of pozzolanic materials, cement, and fly ash:

Important Notes:

• Testing: Tests on representative samples must be conducted promptly (Clause 14.3.2).
• Packing: Pulverized fuel ash bags are typically 30 kg with specific color codes to distinguish from cement bags.
• Rounding Off: Follow IS 2:1960 for rounding off numerical test results to maintain consistency.

This list ensures harmonized testing, sampling, and material specifications crucial for quality control in cement and pozzolanic materials.