Specification for apparatus for flexural testing of concrete

IS 9399 Scope Summary:

• Purpose: Specifies requirements for flexural testing apparatus for cement concrete.
• International Coordination: Aligns with global standards while considering Indian practices (Clause 0.4).
• Rounding Off: Final test/analysis values must be rounded per IS 2-1960, retaining significant figures as per the standard (Clause 0.5).
• Apparatus Features: Detailed in Clauses 3.2.1 to 3.2.4, covering mechanical and dimensional aspects.
• Dimensions: Principal dimensions of apparatus components are specified in Fig. 1 (Clause 3.1).

Key Specification Summary

Rounding Off Rule (IS 2-1960)

• Round final values to the same number of significant figures as specified.
• Use standard rounding (≥5 rounds up).

If you need Fig.1 dimensions or detailed apparatus features, please specify!

IS 9399: Requirements of the Apparatus for Flexural Testing of Concrete

Key Specifications (Clauses 3.1 & 3.2)

• Dimensions: Principal dimensions of the apparatus components must conform to Fig. 1 (typical flexural testing setup).
• Salient Features (Clauses 3.2.1 to 3.2.4):
  • Rigid frame to prevent deflection during testing.
  • Load application via a calibrated proving ring or load cell.
  • Two-point or three-point loading arrangement with specified span length.
  • Supports and loading noses must have hardened steel with smooth rounded edges (radius ~10 mm) to avoid stress concentration.

Typical Flexural Test Setup (Fig. 1)

• Span Length (L): Usually 3 times the depth of the specimen.
• Loading Nose Diameter: ~10 mm radius.
• Support Diameter: ~10 mm radius.
• Specimen Size: Usually prisms of 100x100x500 mm or as specified.

Important Formula for Flexural Strength (Modulus of Rupture):

[ f_r = \frac{PL}{bd^2} ]

Where:

• (f_r) = flexural strength (MPa)
• (P) = maximum load applied (N)
• (L) = span length (mm)
• (b) = width of specimen (mm)
• (d) = depth of specimen (mm)

flowchart LR
    A[Load Application] --> B[Specimen]
    B --> C[Supports]
    B --> D[Load Cell/Proving Ring]
    style A fill:#f9f,stroke:#333,stroke-width:2px
    style B fill:#bbf,stroke:#333,stroke-width:2px
    style C fill:#bfb,stroke:#333,stroke-width:2px
    style D fill:#fbf,stroke:#333,stroke-width:2px

This ensures reliable and standardized flexural testing as per IS 9399.

IS 9399: Dimensions and Material Specifications for Flexural Testing Apparatus

Key Dimensions (Clause 3.1 & Fig. 1)

• Principal parts follow Fig. 1 (typical flexural testing apparatus).
• Roller Diameter: 40 mm for bearing and load applying blocks.
• Apparatus components are dimensioned to ensure proper load application and support span.

Material Specifications (Clause 3.2.1)

• Bearing surfaces: Case hardened steel.
• Hardness: Minimum 480 Vickers Hardness (VH) or equivalent.
• Bearing blocks and load applying blocks are cylindrical rollers of 40 mm diameter.

Additional Notes

• Rounding of test results per IS 2:1960 (Clause 0.5).
• Maintain the same number of significant figures as specified values.

Summary Table

flowchart LR
    A[Load Applying Block] -->|Load applied| B[Specimen]
    B -->|Supported on| C[Bearing Block (40 mm roller)]
    C --> D[Support Frame]

This ensures accurate flexural testing per IS 9399 requirements.

IS 9399: Load Application and Capacity Key Points

Machine Capacity (Clause 4.1)

• Max capacity: 50 kN for load application.
• Machines with higher capacity allowed only if they have a 50 kN range and meet Clauses 4.2–4.5.

Loading System (Clause 3.2.4)

• Load applied via two loading blocks on the top frame.
• Center-to-center distance: 20 cm or 13.3 cm depending on specimen size.
• Blocks rest symmetrically on the specimen.

Loading and Supporting Blocks (Clause 3.2.3)

• Block length ≥ specimen width + 10 mm.
• Bottom frame spans:
  • 60 cm for 15×15 cm specimens.
  • 40 cm for 10×10 cm specimens.
• Top frame loading block positions:
  • 20 cm span for 15×15 cm.
  • 13.3 cm span for 10×10 cm.
• Remove locating bars before loading.

Bearing Surfaces (Clause 3.2.1)

• Material: Case hardened steel.
• Hardness: ≥ 480 Vickers Hardness (VH).
• Blocks: Cylindrical rollers, 40 mm diameter.

Summary Table of Key Dimensions

flowchart LR
    A[Load Application Machine] --> B[Loading Blocks (2)]
    B -->|Center-to-center 13.3 or 20 cm| C[Specimen]
    C --> D[Supporting Blocks on Bottom Frame]
    D -->|Span 40 or 60 cm| E[Base Frame]

This setup ensures uniform load distribution and accurate flexural testing per IS 9399.

IS 9399 – Marking and Certification Key Points

Marking Requirements (Clause 5.1)

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

ISI Certification Mark (Clause 5.1.1)

• Use governed by Indian Standards Institution (Certification Marks) Act.
• ISI Mark assures compliance with Indian Standard under strict inspection, testing, and quality control.
• Continuous ISI surveillance ensures ongoing conformity.
• Licensing conditions for ISI Mark use available from Indian Standards Institution.

Rounding Off (General Clause)

• Values from tests/analysis rounded per IS 2:1960.
• Retain significant digits equal to those in the specified value.

Summary Table: Marking Details

Contact for ISI Licensing & Certification

• Headquarters: Manak Bhavan, 9 Bahadur Shah Zafar Marg, New Delhi 110002
• Phone: 331 01 31, 331 13 75
• Regional and branch offices available nationwide.

flowchart TD
    A[Apparatus] --> B[Mark Manufacturer Name/Trademark]
    A --> C[Mark Date of Manufacture]
    A --> D{Use ISI Mark?}
    D -- Yes --> E[Apply ISI Certification Mark]
    D -- No --> F[No ISI Mark]
    E --> G[Assures Quality & Compliance]

For detailed licensing, contact BIS or refer to ISI Certification Marks Act and Rules.

IS 9399: Calibration and Accuracy of Testing Machines

Key Specifications:

• Calibration Certificate (Clause 4.4):
  A valid calibration certificate must accompany the testing machine.

• Accuracy Limits (Clause 4.2):

  • For loads ≥ 1/5 of full load: Error ≤ ±1% of applied load (high accuracy).
  • For loads < 1/5 of full load: Error ≥ -0.2% of max load (high accuracy).
  • Otherwise, max error allowed: ±1.5%.

• Load Range for Calibration (Clause 4.2.1):
  Calibration loads must be above 100 × smallest load increment on the load scale.

• Rounding Off (Clause 0.5):
  Final test values must be rounded per IS 2-1960 rules, retaining significant digits equal to the standard’s specified value.

Summary Table: Accuracy Limits

Formula for Error Percentage:

[ \text{Error %} = \frac{\text{Measured Load} - \text{Applied Load}}{\text{Applied Load}} \times 100 ]

flowchart LR
    A[Applied Load] --> B{Load Range}
    B -->|≥ 1/5 Full Load| C[Error ≤ ±1%]
    B -->|< 1/5 Full Load| D[Error ≥ -0.2%]
    B -->|Other Cases| E[Error ≤ ±1.5%]
    F[Calibration Certificate] --> G[Machine Delivered]

This ensures testing machine reliability and compliance with IS 9399 standards.

IS 9399: Installation and Mounting Provisions for Flexural Testing Apparatus

Key Specifications:

• Load Applying & Supporting Blocks:

  • Must be held by spring-loaded screws or equivalent to avoid interference with test requirements (Clause 3.2.2).
  • Length should be at least 10 mm greater than the beam width (Clause 3.2.3).

• Mounting Positions for Blocks:

  • Bottom frame spans:
    • 60 cm for 15 x 15 cm specimens
    • 40 cm for 10 x 10 cm specimens
  • Top frame spans:
    • 20 cm for 15 x 15 cm specimens
    • 13.3 cm for 10 x 10 cm specimens (Clause 3.2.3)

• Locating Bars: Must be removed before loading starts.

Dimensional Reference:

• Refer to Fig. 1 (typical flexural testing apparatus) for principal dimensions and layout (Clauses 3.1 & 2.2).

Summary Table: Block Mounting Spans

flowchart TB
    A[Load Applying Block] -->|Length ≥ Beam Width + 10mm| B[Beam]
    B --> C{Mounting Position}
    C -->|15x15 cm| D[Bottom: 60 cm span]
    C -->|15x15 cm| E[Top: 20 cm span]
    C -->|10x10 cm| F[Bottom: 40 cm span]
    C -->|10x10 cm| G[Top: 13.3 cm span]
    H[Spring-loaded screws] -.-> A
    note right of H: Blocks held securely without interference

This ensures proper installation and consistent flexural testing setup per IS 9399.

IS 9399 - Testing Procedure Overview for Flexural Testing of Concrete

Key Points:

• Rounding of Results (Clause 0.5):
  Final test values must be rounded as per IS 2-1960.

  • Retain the same number of significant digits as the specified value in IS 9399.

• Apparatus Dimensions (Clauses 2.2 & 3.1):

  • The flexural testing apparatus must conform to the principal dimensions shown in Fig. 1 of IS 9399.
  • This includes span length, loading nose diameter, and support dimensions to ensure uniformity.

Typical Flexural Testing Apparatus Features:

Rounding Example (IS 2-1960):

flowchart LR
    A[Prepare Specimen] --> B[Set up Apparatus as per Fig.1]
    B --> C[Apply Load at specified rate]
    C --> D[Record Load at Failure]
    D --> E[Calculate Flexural Strength]
    E --> F[Round off as per IS 2-1960]
    F --> G[Compare with Specified Values]

This ensures standardized, reproducible flexural strength testing of concrete specimens.

Quality Control and Inspection - IS 9399 Key Points

Marking & Certification (Clause 5.1.1):

• Apparatus may bear the ISI Certification Mark, indicating compliance with IS standards.
• ISI Mark ensures:
  • Production under a defined system of inspection, testing, and quality control.
  • Continuous conformity checks by ISI.
• Licensing for ISI Mark use is governed by the Indian Standards Institution (Certification Marks) Act.

Quality Control Essentials (General Engineering Practice)

• Inspection Types:
  • Incoming material inspection
  • In-process inspection
  • Final product inspection
• Test Records: Maintain detailed logs of tests and inspections.
• Acceptance Criteria: Defined as per IS standards or contract requirements.
• Rounding Off: Final test values rounded per IS 2:1960 (significant figures as per specified values).

Summary Table: Quality Control Steps

flowchart TD
    A[Raw Material Inspection] --> B[In-Process Inspection]
    B --> C[Final Product Inspection]
    C --> D[Testing & Certification]
    D --> E[ISI Mark Approval]
    E --> F[Market Release]

Note: For detailed test procedures or formulas, refer to specific IS codes related to the product or material under test. IS 9399 primarily governs marking and certification aspects.

IS 9399 - References and Related Standards Summary

• Rounding Off Results:
  As per IS 2:1960, all test or analysis results must be rounded off to the same number of significant digits as specified in IS 9399.

• International Coordination:
  IS 9399 aligns with global standards and local practices to ensure consistency in flexural testing methods.

• Key Reference:

  • IS 2:1960 — Rules for rounding off numerical values.
  • IS 9399:1979 (Reaffirmed 2004) — Standard for flexural testing apparatus and procedures.

• Dimensions:
  Clause 3.1 specifies principal dimensions of flexural testing apparatus components (see Fig. 1 in IS 9399).

Important Notes:

• Always refer to IS 2:1960 for rounding off calculations.
• IS 9399 is harmonized with international standards for testing concrete flexural strength.
• For apparatus design, consult Fig. 1 in IS 9399 for exact dimensions.

flowchart LR
    A[Test/Analysis Result] --> B{Round off as per IS 2:1960}
    B --> C[Keep same significant digits as IS 9399]
    C --> D[Compare with specified values]
    D --> E{Comply / Not Comply}

This ensures accuracy and uniformity in reporting flexural test results.