Handbook of Quality Control for Construction of Roads and Runways
1984 Edition

1. Equipment & Materials

• Mild steel plates with thickness of 25.4 mm and varying diameters (e.g., 762 mm to 154 mm).
• Hydraulic jack with 20-ton capacity controlled remotely.
• Proving ring with a 25-ton rating equipped with dial gauge.
• Ball bearing plates of 25 mm thickness and 100 mm diameter featuring center grooves.
• A 3-meter datum bar with stands and dial gauge clamps.

2. Equipment for Standard Penetration Tests

• Thermostatically controlled constant temperature bath.
• Laboratory-scale petrol gas generator or equivalent heating device.
• Automatic penetrometer adjustable per IS 1203-1958 specifications.
• Soxhlet extraction setup.
• Laboratory mixer with heating jacket of 0.02 m³ capacity.
• Hubbard-field stability apparatus.
• Marshall compaction device conforming to ASTM 1559-62 T.
• Remote reading thermometers.

3. Concrete and Material Testing Tools

• Vicat needle apparatus as per IS 269-1967.
• Moulds for prisms and cubes (100x100x500 mm, 150/100 mm).
• Air permeability testing apparatus.
• High-frequency mortar cube vibrator.
• Concrete mixer of 1 cubic foot capacity.
• Vibrating table sized 1m x 1m conforming to IS 2514-1963.
• Test equipment for flakiness index, aggregate impact, and Los Angeles abrasion (IS 2386).
• Flow table and slump test devices.
• Specific gravity measurement apparatus (IS 2386 Part III).

4. Aggregate Grading Example

1. Importance of Quality Assurance

• Guarantees structural durability, safety, and optimal function.
• Reduces defects and avoids rework.
• Ensures adherence to specified standards.

2. Prerequisites for Effective Quality Control

• Employ trained engineers and technicians.
• Utilize calibrated and reliable testing instruments.
• Follow standardized IRC and IS code procedures.
• Use approved materials that meet specifications.
• Keep thorough documentation of tests and inspections.

3. Categories of Quality Control

• Control of incoming materials.
• Monitoring during construction processes.
• Final product verification.

4. Training Initiatives

• Regular sessions on testing protocols, data interpretation, safety, and environmental guidelines.

Typical Quality Control Parameters Table

Quality Control Flowchart

flowchart LR
    A[Qualified Staff] --> B[Proper Equipment]
    B --> C[Standard Procedures]
    C --> D[Material Compliance]
    D --> E[Documentation]
    E --> F[Effective QC]

In summary, quality control requires skilled personnel, appropriate equipment, adherence to codes, and systematic record-keeping.

Although IRC SP 11 does not detail explicit clauses on sub-base courses, standard pavement design and IRC recommendations guide the following:

• Purpose: Offers load support, distributes traffic loads, and prevents fine material contamination from the subgrade.
• Material: Well-graded granular substances such as gravel, crushed rock, or sand-gravel blends.
• Thickness Range: Normally from 150 mm to 300 mm, depending on traffic volume and subgrade quality.
• Compaction: Achieve at least 95% of Proctor density to guarantee stability.

Typical Parameters:

Thickness Estimation Formula: [ t = k \times \sqrt{W} ] where:

• t = sub-base thickness (mm)
• W = design wheel load (kN)
• k = empirical factor based on subgrade and material

Pavement Layer Sequence

flowchart TD
    Subgrade --> Subbase[Sub-base Layer]
    Subbase --> Base[Base Layer]
    Base --> Surface[Surface Layer]

Summary: Use well-graded materials compacted to 95% density with thickness tailored to traffic and subgrade conditions.

Stone soling serves as a traditional sub-base layer but is less favored today due to inadequate load distribution and risk of sinking on weak soils.

Key Criteria:

• Stones must be hard, durable, and free from weathered or flaky pieces.
• Nominal sizes range between 40 mm and 75 mm.
• Typical thickness lies between 100 mm and 150 mm.
• Proper compaction is necessary to reduce settlements.
• Avoid usage on soft or saturated subgrades to prevent sinking.

Quality Checks:

• Test for Aggregate Crushing Value (ACV), Flakiness Index, and Water Absorption.
• Ensure uniform grading and cleanliness.

General Practice Table:

Process Flow

flowchart LR
    Quarry --> Quality_Check[Material Inspection]
    Quality_Check --> Size_Selection[Select Stone Size]
    Size_Selection --> Layering[Apply Layer Thickness]
    Layering --> Compaction[Compact Properly]
    Compaction --> Placement[Place on Suitable Subgrade]

Note: Stone soling is increasingly replaced by granular sub-base or water-bound macadam for improved performance.

Thin Bituminous Premix Carpet (Clause 5.4)

• Mix Types: Open-graded or dense-graded.
• Binder Content: Maintained within ±2% of specified value.
• Tack Coat: Evenly applied at prescribed rates before premix application.
• Mixing: Preferably mechanically done; aggregates heated when using straight-run bitumen.
• Rolling: Performed immediately after spreading; roller wheels kept moist without using fuel oil.
• Seal Coat: Applied if open-graded mix, following surface dressing guidelines.
• Traffic Restrictions: Allowed post cooling for straight-run bitumen or after curing for cut-back bitumen.

Quality Control Testing (Table 5.2)

Asphaltic Concrete Surfacing (Clause 5.5)

• Follow IRC 29-1968 standards.
• Binder temperature: 150–177°C; aggregate temperature: 155–163°C; temperature difference ≤14°C.
• Binder content variation permitted ±0.3% by mix weight.
• Mechanical mixing and spreading using pavers with screeds.
• Compaction to achieve specified thickness.

Aggregate Gradation Example

Key Tests and Their Frequencies

Notes:

• Standard Proctor test defines optimum moisture content (OMC) and maximum dry density (MDD).
• Field dry density should be at least 95% of MDD.
• Moisture during compaction must be within ±2% of OMC.

Compaction Control Workflow

flowchart TD
    A[Sample Borrow Material] --> B[Laboratory Testing]
    B --> C{Tests}
    C -->|Gradation, Plasticity, Proctor| D[Determine OMC & MDD]
    C -->|CBR| E[Strength Evaluation]
    D --> F[Field Compaction]
    F --> G[Moisture Content Verification]
    F --> H[Dry Density Measurement]
    G --> I{Is Moisture within ±2% OMC?}
    I -->|Yes| H
    I -->|No| F

Ensures earthwork meets required compaction and strength.

Recommended Tests & Frequencies (Table 2.1)

Key Guidelines

• Use Standard Proctor to determine optimum moisture and max dry density.
• CBR test critical for strength evaluation.
• Inspect and limit deleterious materials.
• Frequent moisture checks to ensure proper compaction.

Record Keeping

• Maintain test data in serially numbered registers.
• Link test results with payment documentation.

Summary Table

Process Flow

flowchart TD
    A[Borrow Material Sampling] --> B[Laboratory Analysis]
    B --> C[Test Records]
    C --> D[Quality Assessment]

Statistical Quality Control Overview

• Control limits for aggregate gradation are calculated by:

  [ LCL = \bar{x} - r \times s ] [ UCL = \bar{x} + r \times s ]

  where:

  • (\bar{x}) = mean value
  • (s) = standard deviation
  • (r) = tolerance coefficient (e.g., 1.28 for 90% confidence)

• Standard deviation is computed as:

  [ s = \sqrt{\frac{\sum (x_i - \bar{x})^2}{n-1}} ]

• Coefficient of variation:

  [ CV = \frac{s}{\bar{x}} \times 100% ]

Tolerance Levels

Procedure Summary

1. Collect test data (e.g., sieve analysis).
2. Calculate mean and standard deviation.
3. Select tolerance factor based on confidence level.
4. Compute upper and lower control limits.
5. Plot control charts to monitor process stability.

Workflow Diagram

flowchart TD
    A[Gather Test Data] --> B[Calculate Mean & Std Dev]
    B --> C[Choose Tolerance Factor]
    C --> D[Calculate Control Limits]
    D --> E[Plot Control Chart]
    E --> F{Within Limits?}
    F -- Yes --> G[Process Stable]
    F -- No --> H[Investigate & Correct]

This approach aids in early detection of deviations and maintains consistent quality.

Summary of Essential Testing Apparatus

These tools collectively facilitate comprehensive quality assessments in road and runway construction.

Overview of Sample Forms for Quality Control Tests (Q/R Series)

• Q/R/1: Borrow Material Properties
• Q/R/2: Compaction Characteristics of Earthwork, Gravel, Stabilized Layers
• Q/R/3: Aggregate and Binding Material Properties for WBM
• Q/R/4: Brick Properties for Sub-base and Base Layers
• Q/R/5: Aggregate Characteristics for Bituminous Layers
• Q/R/6: Rate of Binder and Aggregate Spread, Bitumen Content
• Q/R/7: Temperature Logs for Bituminous Works
• Q/R/8: Surface Evenness Records
• Q/R/9: Coarse Aggregate for Concrete
• Q/R/10: Fine Aggregate for Concrete
• Q/R/11: Water Used in Bridge Construction
• Q/R/12: Cement Concrete Properties

Key Tables and Specifications

• Aggregate grading control charts use sieve analysis data with Upper and Lower Control Limits for monitoring quality.
• Proctor density and CBR values documented for borrow materials.
• Test frequencies follow guidelines (e.g., Aggregate Impact Value: 1 test per 200 m³).
• Quality records maintained in serially numbered registers, linked with financial billing every third running bill.

Aggregate Grading Statistical Control Example

Though IRC SP 11 does not specify formulas, it highlights the organizational and statistical framework for quality control in road projects.

Core Responsibilities of QC Units

• Material testing to verify specification compliance using statistical sampling.
• Continuous monitoring of construction processes.
• Maintaining records and generating reports.
• Identifying defects and implementing corrective measures.
• Conducting training and raising awareness among site personnel.

Typical QC Organizational Structure

• Chief Quality Control Engineer overseeing:
  • Material Testing Laboratory
  • Field Inspection Teams
  • Documentation and Data Analysis Section
  • Training and Compliance Personnel

Statistical Quality Control Approach

• Employ sampling plans and control charts (e.g., X-bar and R charts).
• Apply acceptance criteria based on statistical confidence intervals.

Organizational Chart

graph TD
    A[Chief QC Engineer]
    A --> B[Material Testing Lab]
    A --> C[Field Inspection Team]
    A --> D[Documentation & Data Analysis]
    A --> E[Training & Compliance]

For detailed sampling and acceptance guidelines, refer to IS 2500 series and IRC material testing manuals.

Surface Evenness Checking Procedure (Clauses 3.2.5 & 6)

• Equipment Required:

  • Straight-edge of 1.5 meters length.
  • Two graduated wedges.
  • Personnel: Two operators to hold the straight-edge and one supervisor to record measurements.

• Methodology:

  1. Position the straight-edge on the pavement surface.
  2. Insert the wedge at the largest gap under the straight-edge and record the measurement.
  3. Slide the straight-edge forward or backward by approximately 1.5 meters and repeat.
  4. Mark locations where unevenness exceeds permissible limits.

• Measurement Significance:

  • Wedge reading quantifies maximum deviation or undulation at the point.

Maximum Allowable Surface Irregularities

Measurement Setup Diagram

graph LR
A[Straight-edge (1.5m)] -- placed on --> B[Surface]
B -- gap measured by --> C[Graduated Wedge]
C -- reading recorded by --> D[Supervisor]
E[Operators] -- hold --> A

Note: Surfaces exceeding tolerances should be corrected by grinding, patching, or relaying to achieve smoothness.

This process is vital for ride comfort and pavement durability.

Aggregate Characteristics

• Gradation (% passing IS sieve sizes), for example for water bound macadam/base courses:

• Aggregate Impact Value (IS 2386 Part IV):

  • Frequency: 1 test per 200 m³.
  • Indicates resistance to impact.

• Flakiness Index:

  • Measures particle shape; lower values preferred for better compaction.

Binding Material

• Plasticity Index of filler (IS 2720 Part V):

  • Frequency: 1 test per 25 m².
  • Affects workability and stability.

• Moisture Content and Compaction:

  • Natural moisture content test: 1 per 250 m³.
  • Standard Proctor test to determine optimum moisture and max dry density.

Compaction Properties

Quality Assurance

• Maintain records in proforma Q/R/3.
• Use statistical control charts to ensure gradation within UCL and LCL.

Aggregate Gradation Control Example

Specifications per IRC SP 11 Clause 5.5 and IRC 29-1968

• Reference standard: IRC 29-1968 for a 4 cm thick asphaltic concrete surface course.
• Materials: Bituminous binder, filler material, fine and coarse aggregates as per IRC 29.
• Base preparation as per Clause 5.2.3.1; may include bituminous leveling course for uneven surfaces.
• Mix design must conform to IRC criteria for gradation and binder content.
• Binder content allowed variation: ±0.3% by weight of mix.
• Mixing and laying:
  • Binder temperature: 150–177°C.
  • Aggregate temperature: 155–163°C.
  • Max temperature difference: 14°C.
  • Use mechanical mixers and pavers.
  • Immediate rolling after placement.

Quality Control Tests (Table 5.2)

Typical Aggregate Gradation Limits

Quality Control Responsibilities

• Director of Quality Control: Oversees policy enforcement, training, research coordination, report evaluation, and supervision of major projects.
• Quality Control Divisions: Support field officers, conduct inspections and material tests, recommend improvements, identify materials, and train site personnel.

Standardized Test Forms (Q/R Series)

• Test frequencies are as specified in the handbook.
• Records are maintained in serially numbered registers and linked to payment bills every third running bill.

Key Tables and Specifications

• Aggregate grading control charts use statistical limits (UCL, LCL) for compliance verification.
• Proctor density, CBR, deleterious content, and moisture content are recorded for borrow materials.
• Refer to IRC standards (e.g., IRC 14, 15, 19, 20, 27, 29, 36, 48, 57) for detailed specifications.

Statistical Quality Control

• Plot sieve analysis results against specified limits.
• Verify that mean and control limits lie within specification boundaries.
• Deviations indicate non-conformity.

Documentation Flowchart

flowchart TD