Specification for apparatus for determining constituents of fresh concrete

IS 7325: Scope & Key Specifications Summary

• Scope: Specifies apparatus requirements for determining constituents of fresh concrete, ensuring standardization in testing.

Key Points from IS 7325:

• Marking (Clause 6.1):
  Each apparatus component must be indelibly marked with:

  • Manufacturer’s name or registered trademark
  • Date of manufacture
    (Marking should not affect apparatus performance)

• Rounding Off (Clause 0.3):
  Test or analysis results must be rounded per IS 2:1960, retaining the same number of significant digits as specified values.

• Materials (Clause 5.1):
  Materials for apparatus components are specified in Table 1 (not fully provided here), ensuring durability and accuracy.

Apparatus Dimensions & Components:

• Standard sieves:

  • 475 mm IS Sieve
  • 150-micron IS Sieve

• Supporting Mesh & Spider:
  Detailed plans for spider supporting mesh and base for sample bucket are provided with all dimensions in millimeters.

• Funnel for Material Transfer:
  Dimensions and design ensure efficient sample transfer.

Summary Table (Example):

flowchart LR
    A[Fresh Concrete Sample] --> B[Sieving Apparatus]
    B --> C{Sieves}
    C --> C1[475 mm IS Sieve]
    C --> C2[150 micron IS Sieve]
    B --> D[Supporting Mesh & Spider]
    B --> E[Funnel for Transfer]
    B --> F[Sample Bucket Base]

Note: For detailed dimensions and materials, refer to full IS 7325 tables and figures.

IS 7325 - Working Principle & Key Specifications

The apparatus determines proportions of cement, fine, and coarse aggregates in fresh concrete (max aggregate size ≤ 40 mm).

Working Principle (Clause 2)

• Separation of concrete components by washing and sieving.
• Use of nested sieves (e.g., 475 mm IS sieve, 150-micron IS sieve) to separate fine and coarse aggregates.
• Washing sample with fine spray to remove cement paste.
• Use of a bucket-shaped container immersed in a water tank to facilitate washing without loss of material.

Key Specifications

Apparatus Layout (Simplified)

flowchart LR
    A[Concrete Sample] --> B[Bucket Container]
    B --> C[Water Tank with Tap & Baffle]
    C --> D[Washing with Fine Spray]
    D --> E[Nested Sieves]
    E --> F[Separated Cement, Fine & Coarse Aggregates]

This method ensures accurate proportion determination by washing out cement paste and separating aggregates by size.

IS 7325: Dimensions & Specifications of Apparatus Components

Key Dimensions (All in mm)

Material Specifications (Clause 5.1)

• Corrosion-resistant metals such as stainless steel, chromium or nickel plated steel sheet.
• Thickness:
  • Tank: 2.0 mm
  • Baffle plate: ~1.6 mm

Marking Requirements (Clause 6.1)

• Manufacturer’s name or trademark
• Date of manufacture
  (Marked clearly without affecting apparatus performance)

Summary Diagram of Main Tank Setup (Fig. 3)

flowchart TB
    A[Subsidiary Water Tank]
    B[Flexible Pipe & Tap (20 mm below top)]
    C[Main Water Tank (300 mm dia × 300 mm depth)]
    D[Overflow Spout (5 mm below rim)]
    E[Baffle Plate (70×100 mm, 1.6 mm thick)]
    F[Bucket Container]

    A --> B --> C
    C --> D
    C --> E
    C --> F

This ensures accurate weighing for concrete constituent tests with proper immersion and water level control.

IS 7325 - Parts and Accessories: Key Specifications

Marking (Clause 6.1)

• Each component must have:
  • Manufacturer’s name or trademark
  • Date of manufacture
• Marking should not affect apparatus performance.

Materials for Apparatus Components (Clause 5.1 & Table 1)

Dimensional Details (Clause 3.1 & Figures)

• Dimensions of apparatus parts as per Fig. 1 (e.g., 5 kg semi-automatic balance)
• Tolerances nominal unless specified.

Accessories & Components

• Fine spray for washing samples
• Spider supporting mesh (dimensions as per Fig. 4)
• Base for sample bucket support
• Funnel for material transfer (Fig. 5)
• Counterpoise for weighing in air and water
• Subsidiary & main water tanks
• Flexible connections

Summary Diagram (Parts & Material Flow)

graph LR
A[Bucket & Handle] -->|Material| B[Non-corrodible Metal]
C[Tank] -->|Material| B
D[Spider] -->|Material| E[Brass]
F[Stand] -->|Material| G[Cast Iron]

For detailed dimensions, refer to IS 7325 Figures 1, 4, and 5. Ensure smooth finishes and corrosion resistance as specified for durability and accuracy.

IS 7325 - Materials for Apparatus Construction (Clause 5.1 & Table 1)

Key Notes:

• Use non-corrodible metals for parts in contact with cement to prevent corrosion.
• Surfaces must have a smooth finish to avoid material adherence and ensure accurate measurement.
• Brass and cast iron are specified for spider and stand respectively, per relevant IS standards.

References:

• IS 292-1961: Specification for brass ingots and castings.
• IS 210-1970: Specification for grey iron castings.

flowchart LR
    A[Bucket & Handle] -->|Material| B[Stainless Steel / Chromium or Nickel Plated Steel]
    C[Tank] -->|Material| B
    D[Spider] -->|Material| E[Brass (IS 292-1961)]
    F[Stand for Sample Bucket] -->|Material| G[Cast Iron (IS 210-1970)]

This ensures durability and accuracy in fresh concrete constituent determination apparatus.

IS 7325: Marking and Identification (Clause 6.1 & 6.1.1)

• Mandatory Markings on Each Apparatus Component:

  • Manufacturer's name or registered trademark (or both).
  • Date of manufacture.
  • Markings must be clear, indelible, and not interfere with apparatus performance.

• Optional Marking:

  • ISI Certification Mark may be applied per Indian Standards Institution rules.
  • Indicates compliance with quality, inspection, and testing standards.

Material Specifications (Table 1, Clause 5.1)

Notes:

• Marking location should avoid affecting apparatus function.
• ISI Mark usage is governed by the Indian Standards Institution Certification Marks Act.
• For detailed dimensions and apparatus plans, refer to figures in IS 7325 (e.g., Fig. 4 Nested Sieves, Fig. 5 Funnel).

flowchart TD
    A[Apparatus Component] --> B[Mark Manufacturer Name/Trademark]
    A --> C[Mark Date of Manufacture]
    A --> D{Optional: ISI Certification Mark}
    D --> E[Complies with ISI rules]

This ensures traceability and quality assurance per IS 7325.