Bitumen Mastic, Anti-Static and Electrically Conducting Grade
1977 Edition

Overview of Scope under IS 8374

1. Bitumen Characteristics (Refer Table 1)

• Common binders include industrial bitumen grades 90/15 and 75/15 (per IS:702-1961).

2. Gradation of Aggregates and Fillers (Refer Table 2)

3. Labeling Instructions (Clause 7.5)

• Labels should clearly indicate: sample ID, material and binder types, aggregate types, applicable specifications, mixing plant details, dates for mixing, laying, and sampling, site information, number and thickness of layers, foundation details, surface treatment, and required tests.

This section ensures traceability and quality management for bituminous materials under IS 8374.

Terminology and Definitions (Clause 2.0)

• Terminology aligns with definitions provided in IS 334-1965.
• Additional terms specific to bitumen mastic and testing equipment are included.

Bitumen Requirements (Clause 3.1, Table 1)

Typical bitumen grades are 90/15 and 75/15 (IS 702-1961).

Aggregate and Filler Particle Size Distribution (Clause 3.2, Table 2)

Testing Equipment (Clause 2.1)

• Equipment must meet precision and calibration requirements.
• Illustrative setup (Fig. 1) depicts typical apparatus, including penetration testing instruments.

Material Properties and Requirements under IS 8374

Bitumen Properties (Clause 3.1, Table 1)

Common binders: industrial bitumen grades 90/15 and 75/15 per IS: 702-1961.

Aggregate and Filler Gradation (Clause 3.2, Table 2)

Aggregates and fillers must be chemically inert to ensure stability.

Notes

• Bitumen properties influence durability and performance.
• Particle size distribution controls texture and mechanical strength.
• Precision instruments with specified voltage and accuracy are required for testing (Clause 2.1).
• Electrical resistance tests (Clause 6.2 & Appendix C) apply to floor coverings for safety assurance.

IS 8374: Essential Requirements for Bitumen and Aggregates

Bitumen Physical Characteristics (Refer Table 1)

• Industrial bitumen grades 90/15 and 75/15 as per IS:702-1961 meet these criteria.

Aggregate and Filler Particle Size Distribution (Refer Table 2)

• Aggregates and fillers must be inert and comply with specified gradation.

Compliance Criteria (Clause 7.4)

• Representative laboratory samples must successfully meet all test requirements for the entire lot to be considered compliant.

Visual Summary: Bitumen and Aggregate Specifications

IS 8374: Hardness Number Testing Protocols and Formula

Definition (Clause A-1.1)

• The hardness number (HN) represents the penetration depth, measured in hundredths of a centimeter, of a flat-ended steel rod (6.35 mm diameter) into the bitumen mastic.
• An applied load of 31.7 kg (equivalent to 100 kg/cm² pressure) is maintained for 1 minute at a temperature of 35 ± 0.5 °C.

Sample Preparation (Clause A-3.1.1)

• Mastic samples should be at least 100 mm in diameter and 25 mm thick.
• Samples are taken in duplicates and finished with a floating technique.
• Remelting of samples is not permitted.

Testing Procedure (Clause A-3.1.2)

• Samples must be cooled for a minimum of 3 hours in air or 1 hour in cold water.
• Following this, condition samples by immersing in water at 35 ± 0.5 °C for at least 1 hour prior to testing.
• Maintain the specified temperature throughout the test.

Measurement Protocol (Clause A-3.1.5)

• At least five readings should be recorded, spaced at least 25 mm apart and located at least 25 mm from the edges.
• Readings deviating by more than 2 units from the mean should be discarded.
• The average of the remaining valid readings is calculated; if fewer than four valid readings remain, the sample must be rejected and retested.

Equipment (Refer Fig. 1)

• Indenter rod with 6.35 mm diameter
• Lever mechanism applying 31.7 kg load
• Calibrated dial gauge for measuring penetration depth

Formula Summary

[ \text{Hardness Number (HN)} = \text{Penetration depth in hundredths of centimeters} ]

Remarks

• This number provides a direct quantification of penetration under controlled loading and temperature, ensuring mastic uniformity and quality control.

This structured procedure guarantees consistent and reliable hardness measurements in alignment with IS 8374.

IS 8374: Detailed Testing Procedures

1. Physical Properties of Bitumen (Refer Table 1, Clause 3.1)

2. Electrical Resistance Measurement (Clauses 2.1 & 6.2)

• Utilize an insulation tester with a nominal voltage of 500 V DC; for resistances exceeding 10^6 ohms, a voltage of 1000 V DC is employed.
• The instrument must have an accuracy within ±5% and limit power dissipation to a maximum of 3 watts in the test specimen.
• Voltage is applied only for the minimal duration necessary to prevent sample heating.
• Tests are conducted at 27 ± 2 °C with relative humidity below 70%.
• Liquid electrodes are applied on two 25 mm² areas spaced 50 ± 6 mm apart, followed by metal contacts.
• Resistance readings are recorded after a conditioning period ranging from 15 minutes to 2 hours post-preparation.

3. Sampling and Compliance (Clause 7.4)

• Test a representative laboratory sample.
• The lot is deemed compliant only if the sample meets all specifications.

Diagram: Electrical Resistance Test Setup

graph LR
A[Surface to be tested] --> B[Apply liquid electrodes (25 mm²)]
B --> C[Attach metal contacts]
C --> D[Measure resistance over 50 ± 6 mm gap]
D --> E[Record resistance after 15 min to 2 hrs]

For comprehensive testing, refer to the detailed IS methods.

IS 8374: Sampling Protocols and Conformity Determination

1. Compliance Requirements (Clause 7.4)

• A laboratory sample representing the entire lot must be tested against all specified criteria.
• The lot is considered conforming only if the sample passes all tests.

2. Sampling and Testing Methodology (Clause 6.2)

• Apply liquid electrodes and metal contacts as described in Appendices B and C immediately after surface preparation.
• Maintain test sample conditions at 27 ± 2 °C and relative humidity below 70%.
• Conduct resistance measurements between 15 minutes and 2 hours after preparation.
• Avoid moisture contamination by preventing breathing on the sample.

3. Bitumen Physical Property Requirements (Clause 3.1, Table 1)

4. Labeling Details (Clause 7.5)

• Labels must include:
  • Authority name and address
  • Sample identification number
  • Material and binder types
  • Specification references
  • Mixing plant location
  • Dates of mixing, laying, and sampling
  • Sampling site and position
  • Number and thickness of layers
  • Foundation and surface treatment
  • Tests to be conducted

Process Flowchart

flowchart TD
    A[Sample Preparation] --> B[Apply Electrodes & Contacts]
    B --> C[Condition at 27 ± 2 °C & RH < 70%]
    C --> D[Conduct Resistance Test (15 min - 2 hrs)]
    D --> E{Test Results}
    E -- Pass All --> F[Lot Conforms]
    E -- Fail Any --> G[Lot Does Not Conform]

Summary: Representative sampling and testing under controlled conditions determine lot conformity.

IS 8374: Guidelines for Marking and Storage

Marking Details (Clauses 7.5, 8.1, 8.2)

• Specimen Labeling:
  • Each sample must bear a label linked to a record that includes:
    • Name and address of the certifying authority
    • Unique sample identification number
    • Types of material, binder, and aggregates
    • Reference to applicable specifications
    • Mixing plant and its location
    • Dates of mixing, laying, and sampling
    • Sampling site and position
    • Number and thickness of layers
    • Details of foundation and surface treatment
    • Tests required
• Stored Blocks (Clause 8.1):
  • Manufacturer's name and date of manufacture should be cast onto the blocks.

BIS Standard Mark (Clauses 8.2, 8.2.1)

• The use of the Standard Mark is governed by the BIS Act, 1986.
• Manufacturers are required to obtain proper licensing from BIS for its use.
• Marking facilitates traceability and quality verification.

Labeling Information Summary

Process Flow

flowchart TD
    A[Block Manufacture] --> B[Marking: Date & Manufacturer]
    B --> C[Storage]
    C --> D[Sampling and Labeling]
    D --> E[Testing Laboratory]
    E --> F[Results & Certification]

This procedure ensures traceability from production through testing.

IS 8374: Protocol for Hardness Evaluation of Bitumen Mastic

Sample Preparation (Clause 3.1.1)

• Samples should be at least 100 mm in diameter or 100 cm² in area, with a thickness of 25 mm.
• Samples are collected directly from the mixer without reheating.
• Ensure uniform thickness and a level surface.

Test Temperature Control (Clause A-3.1.2)

• Cool samples for a minimum of 3 hours in air or 1 hour in running cold water.
• Subsequently, immerse samples in water at 35 ± 0.5 °C for at least 1 hour before testing.
• Maintain this temperature consistently during the test.

Hardness Number Definition (Clause 1.1)

• The hardness number equals the penetration depth (in hundredths of centimeters) of a 6.35 mm diameter steel rod under a 31.7 kg load applied for 1 minute at 35 °C.
• The applied load corresponds to a pressure of 100 kg/cm².

Testing Procedure and Data Collection (Clause 3.1.5)

• Obtain at least five measurements spaced 25 mm apart and at least 25 mm from sample edges.
• Average the measurements, discarding any that differ by more than 2 units from the mean.
• If fewer than four valid readings remain, reject the sample and repeat testing.

Apparatus Components (Fig. 1)

• Indentation pin and spindle
• Calibrated dial gauge
• Weight and lever mechanism
• Temperature control devices
• Support and adjustment screws

Summary Table of Test Parameters

flowchart TD
    A[Sample Preparation] --> B[Cooling: 3 hrs air or 1 hr water]
    B --> C[Immersion at 35°C for 1 hr]
    C --> D[Indentation Testing]
    D --> E[Record Multiple Readings]
    E --> F[Data Validation and Averaging]

This method ensures accurate and reproducible hardness measurements.

IS 8374: Specifications for Testing Devices and Electrode Solutions

Composition of Liquid Electrodes (Appendix B, Clause 1.1.1)

• Prepare by mixing:
  • Water: 200 parts
  • Soft soap: 1 part
  • Potassium chloride (KCl): 10 parts

Testing Instruments (Appendix B, Clause 2.1)

• Use an insulation resistance tester with the following characteristics:
  • Nominal open-circuit voltage: 500 V DC (standard)
  • For resistances above 10^6 ohms, use 1000 V DC
  • Accuracy within ±5%
  • Power dissipation limited to ≤ 3 watts in the test specimen
• Apply voltage only for the shortest duration necessary to prevent overheating.

Test Configuration (Appendix C)

• Apply liquid electrodes over two areas approximately 25 mm² each.
• Maintain the distance between the two electrode edges at 50 ± 6 mm.
• Metal contacts are placed on the wetted electrode surfaces.
• Measurements are conducted after conditioning the specimen at 27 ± 2 °C with relative humidity less than 70%, waiting 15 minutes to 2 hours before reading.

Summary Table

flowchart LR
    A[Surface Preparation] --> B[Apply Liquid Electrodes (25 mm²)]
    B --> C[Place Metal Contacts]
    C --> D[Condition at 27 ± 2 °C, RH < 70%, 15 min to 2 hrs]
    D --> E[Measure Resistance with Insulation Tester]

This standardizes the electrical resistance measurement of floor coverings.

IS 8374: Procedure for Measuring Electrical Conductance of Floor Coverings

Key Test Parameters and Procedure (Clause 6.2 and Appendix C)

• Surface Preparation: Clean the test surface thoroughly and apply liquid electrodes (composition per Appendix B) on two discrete areas of approximately 25 mm² each.
• Electrode Spacing: Maintain a distance of 50 ± 6 mm between the facing edges of the electrodes.
• Environmental Conditions: Conduct the test at 27 ± 2 °C and relative humidity below 70%.
• Timing: Resistance measurements should be taken between 15 minutes and 2 hours after application of electrodes.
• Moisture Control: Avoid breathing on the sample surface during the test to prevent moisture interference.

Testing Equipment Requirements (Clauses 2.1 and Appendix B)

Acceptable Electrical Resistance Range (Clause 5.2)

• The bitumen mastic should exhibit resistance between 5 × 10⁴ ohms and 2 × 10⁶ ohms.

Test Setup Overview

graph LR
A[Prepared Surface] -->|Apply Liquid Electrodes| B[Two Areas (~25 mm² each)]
B -->|Maintain 50 ± 6 mm Gap| C[Apply Metal Contacts]
C --> D[Measure Electrical Resistance]
D --> E[Verify Resistance Within 5 × 10⁴ to 2 × 10⁶ Ω]

Additional Notes

• Use insulation testers compliant with IS 8374 Appendix B.
• Prevent moisture contamination during testing.
• Testing is performed on a single surface only.

This procedure ensures accurate and reliable electrical conductivity measurements as prescribed by IS 8374.