Quality Assurance Handbook for Rural Roads, Volume II
2016 Edition

Earthwork in Excavations – Essential Formulas, Tables & Standards (MORD 21 / IRC SP-11)

1. Material Testing (Clause 302.A)

2. Construction and Workmanship (Clause 302.B)

• Moisture Content Measurement:
  • Oven Dry Method (IS 2720 Part 2)
  • Sand Bath, Infrared Lamp, Calcium Carbide Techniques
• In-situ Density and Compaction Degree:
  • Sand Replacement Method
  • Core Cutter Method
  • Nuclear and Non-Nuclear Density Gauges
• Surface Evaluations:
  • Horizontal Alignment (Clause 302.10)
  • Surface Levels (Clause 302.11)
  • Surface Smoothness (Clause 302.12)

3. Equation for Degree of Compaction:

[ \text{Degree of Compaction} (%) = \frac{\text{Field Dry Density}}{\text{Maximum Dry Density (Proctor)}} \times 100 ]

4. Surface Smoothness Test (from Clause 1.5 IRC SP-11):

• Employ a 1.5 m straightedge moved progressively along the surface.
• Detect undulations using a wedge gauge.
• Count and mark depressions exceeding allowable limits.

5. Summary Table for Earthwork Testing

Essential Specifications and Tests for Subgrade Construction (Clause 303, MORD 21)

A) Material Evaluations:

B) Construction and Workmanship Checks:

Degree of Compaction Equation:

[ \text{Degree of Compaction} = \frac{\text{Field Dry Density}}{\text{Maximum Dry Density (Proctor)}} \times 100 ]

Typical Acceptable Limits (per IRC/SP-11 & MORD):

• Moisture Content: ±2% of Optimum Moisture Content (OMC)
• Degree of Compaction: Minimum 95% of Maximum Dry Density
• CBR: Minimum 5% for subgrade

Subgrade Quality Control Flow Diagram

flowchart TD
    A[Material Testing] --> B[Grain Size, Plasticity, CBR]
    B

Essential Material Testing Techniques as per IS Code MORD 21

1. Aggregate Testing

• Crushing Strength: Evaluates aggregate resistance to crushing forces.
• Aggregate Impact Value (AIV): [ AIV = \frac{\text{Weight of fines passing 2.36 mm sieve after testing}}{\text{Total sample weight}} \times 100 ]
• Flakiness & Elongation Index: Assesses shape qualities.
• Soundness Tests: Utilize Sodium and Magnesium Sulphate (Clauses 402.5, 402.6).
• Polished Stone Value (Clause 402.7): Measures skid resistance.
• Specific Gravity & Water Absorption: (Clause 402.4).

2. Bitumen and Binder Testing

• Penetration Test (Clause 509.21): Determines hardness.
• Ring and Ball Softening Point: Temperature at which bitumen softens.
• Ductility Test: Measures elongation before breakage.
• Elastic Recovery & Separation Tests: For modified bitumen (Clause 511).
• Viscosity at 1500C.
• Thin Film Oven Test: Evaluates aging characteristics.
• Binder and Mix Spread Rate: (Clauses 503.6, 509.21).

3. Water Quality for Construction

• Tests for impurities, organic matter, and harmful content (Clause 600.8).
• Parameters include pH, chloride, sulfate, and turbidity levels.

4. Cement and Lime Testing

• Setting Times (Initial and Final): (Clause 600.5).
• Soundness (Le Chatelier Method): (Clause 800.2).
• Compressive Strength: (Clause 800.3).
• Lime Purity as CaO: (Clause 2000.17).

5. Concrete Testing Procedures

• Workability: Slump test (Clause 800.19).
• Compressive Strength of Cubes: (Clause 800.26).
• Flexural Strength: (Clause 800.27).
• Schmidt Rebound Hammer Test: (Clause 800.23).
• Ultrasonic Pulse Velocity: (Clause 800.24).

Fundamental Calculations and Standards for Compaction and Moisture Content Tests (IS Code MORD 21)

1. Parameters in Compaction Tests:

• Weight of the Mould (W1)
• Weight of Mould plus Compacted Soil (W2)
• Wet Soil Weight = W2 - W1
• Wet Density ((\rho_w)) = Wet Soil Weight / Mould Volume (V)
• Moisture Content (W%) = (Weight of Water / Weight of Dry Soil) × 100
• Dry Density ((\rho_d)) = Wet Density / (1 + W%)

2. Formula for Moisture Content:

[ W% = \frac{W_w}{W_s} \times 100 ]

Where:

• (W_w) = Weight of Water
• (W_s) = Weight of Dry Soil

3. Dry Density Calculation:

[ \rho_d = \frac{\rho_w}{1 + \frac{W}{100}} ]

Where:

• (\rho_w) = Wet Density (g/cm³ or kN/m³)
• (W) = Moisture Content (%)

4. Typical Maximum Dry Density and Optimum Moisture Content Values (IS: 2720 Part 7)

5. Factors Influencing Compaction:

• Water Content: Dry density peaks near optimum moisture.

Essential Tests and Specifications for Bituminous Binder Quality as per MORD 21:

1. Penetration Test (Clauses 507.7 / 506.1.2(a))

• Determines bitumen hardness or consistency.
• Penetration depth measured in 0.1 mm units under standard conditions.
• Typical values for paving grade bitumen: 40-60.

2. Ring and Ball Softening Point (Clauses 507.8 / 504.2(b))

• Temperature at which bitumen softens.
• Indicates susceptibility to temperature changes.
• Typical softening point range: 46-560C.

3. Ductility Test (Clause 504.1)

• Evaluates the stretchability before breaking.
• Standard ductility: Minimum 75 cm at 270C.

4. Absolute Viscosity Test (Clauses 507.5 / 502.14)

• Measures flow resistance.
• Important for modified binders and emulsions.

5. Elastic Recovery Test (Clauses 507.9 / 504.2(c))

• Measures elasticity of modified bitumen.
• Minimum typical value: 50%.

6. Separation Test (Clauses 507.10 / 504.2(d))

• Checks homogeneity and stability of modified binders.

7. Bitumen Emulsion Tests (Clause 506.2.1)

• Includes viscosity, sieve residue, storage stability, and evaporation residue.

Summary Table: Bituminous Binder Tests

Procedures for Viscosity Testing of Bitumen and Cutback Bitumen (IS Code MORD 21, Clause 502.14)

1. Kinematic Viscosity of Cutback Bitumen at 600C (Table 502.14.1)

Reference: IS 1206 (Part 3)

2. Absolute Viscosity Determination Using Cannon Manning Vacuum Capillary Viscometer

• Heat sample to 135 ± 5.50C (max 600C for tars/pitches, 900C for bitumen).
• Fill viscometer to calibration line ± 2 mm.
• Maintain vacuum at 30 ± 0.05 cm Hg.
• Measure flow time (t) after 30 ± 5 min conditioning.
• Calculate viscosity:

[ \text{Viscosity (Poise)} = K \times t ]

where:

• (K) = calibration constant (Poise/s)
• (t) = flow time (seconds)

Reference: IS 1206 (Part 2)

3. Kinematic Viscosity by BS U-Tube Modified Reverse Flow Viscometer

• Equilibrate sample temperature (20–30 minutes).
• Record efflux time (t) between timing marks.
• Calculate kinematic viscosity:

[ \text{Kinematic Viscosity (cSt)} = C \times t ]

where:

• (C) = calibration constant (cSt/s)
• (t) = efflux time (seconds)

4. Brookfield Viscometer

• Operate per manufacturer instructions.
• Set test temperature using thermosel.
• Measure viscosity directly in Poise or millipascal-seconds.

Viscosity Testing Process Flow

flowchart TD
    A[Sample Preparation] --> B[Heating to Test Temperature]
    B --> C[Charge Viscometer]
    C --> D[Measure Flow Time]
    D --> E[Calculate Viscosity]

Guidelines for Concrete Pavement Construction and Testing (MORD 21, Clauses 2000.20–2000.32)

1. Concrete Mix Design and Materials

• Follow mix design standards per IRC:44 and IS:10262.
• Use approved water sources (Clause 2000.32).
• Employ premoulded joint fillers and approved sealing compounds.
• Maintain aggregate gradation and moisture content as per Clause 400.

2. Pavement Thickness and Dimensions

• Adhere to designed thickness and width.
• Ensure straightness of side forms.
• Dowel bars: size, spacing, depth, and alignment must comply with specifications.
• Transverse contraction joints: maintain specified width and depth.

3. Workability and Compaction

• Assess workability using slump or compaction factor tests.
• Use needle, screed, and plate vibrators for compaction.
• Follow precautions for concreting in hot and cold weather.

4. Flexural Strength Testing (IS:516)

• Beam size: 10 × 10 × 50 cm.
• Effective span length (L): 40 cm; Breadth (B): 10 cm; Depth (D): 10 cm.
• Flexural strength formula:

[ f_r = \frac{3 W L}{2 B D^2} ]

where:

• (W) = failure load (kg)

• (L) = span length (cm)

• (B) = beam width (cm)

• (D) = beam depth (cm)

• Minimum flexural strength: 40 kg/cm² (wearing course).

• Allowable variation: ±15% of average.

5. Surface Smoothness and Joint Alignment

• Check surface regularity with straightedge or profilometer.
• Confirm joints are properly aligned and sealed.

6. Quality Control Measures

• Conduct a 30 m trial section before full construction.
• Use steel tapes for dimensional verification.
• Perform concrete core density tests to evaluate compaction.

Table: Flexural Strength Test Parameters

Rectangular Concrete Block Pavement Specifications (MORD 21 - Clause 1503)

Materials and References:

• Cement: IS 2000.13 to 2000.15
• Fine and Coarse Aggregates: IS 400, 2000.20 to 2000.31
• Fly Ash: IS 2000.12 to 2000.16
• Water Quality: IS 2000.32
• Admixtures: IS 2000.19

Block Manufacturing and Properties:

• Manufacturing and compaction methods as per standards.
• Block dimensions and thickness specified in Clause 1503.22.
• Compressive strength requirements per IS 800.26.
• Joint width and laying patterns as defined in Clauses 1503.18 and 1503.7.

Subgrade and Subbase:

• Prepared in accordance with IS 303 and IS 401.

Trial Section:

• Performance assessment per Clause 1501.12.

Quality Control Parameters

Typical Block Dimensions and Strength

General Pavement Thickness Formula

[ t = \sqrt{\frac{P}{k \times S}} ]

Where:

• (t) = Pavement thickness (mm)
• (P) = Load or pressure parameter
• (k), (S) = Soil and material constants

Key Standards and Formulas for Pipe Culverts and Vented Causeways (MORD 21)

1. Pipe Culverts

• Straightness Testing (Clause 2000.42):

  • Use rigid straight edge inside pipe bore.
  • Pipe fails if gauge contacts internal surface simultaneously at four locations around circumference.
  • Reverse gauge and recheck studs on opposite edge.
  • Refer IS 458 and IS 3597 for detailed procedures.

• Dimension and Alignment Checks:

  • Horizontal alignment and surface smoothness per Clauses 301.9, 301.10, 301.11.
  • Utilize instruments like levels, straight edges, and measuring tapes.

2. Vented Causeways

• Designed with multiple small openings (pipes or boxes) to permit water flow.
• Earthwork and subgrade construction adhere to Clauses 302 and 303.
• Employ Proctor density, CBR, and moisture content tests (Clauses 302.3, 302.7, 302.8) to ensure embankment stability.

Important Test Methods

Design Formula (Typical for Pipe Culverts)

• Hydraulic Discharge Capacity:

[ Q = A \times V ]

Where:

• (Q) = Discharge (m³/s)
• (A) = Cross-sectional flow area (m²)
• (V) = Flow velocity (m/s)

Detailed content not provided.

Aggregate Quality and Restrictions on Deleterious Materials (MORD 21)

1. Maximum Allowable Limits of Deleterious Substances (Clause 2000.27.1 - Table 2000.27.1)

• Note: Material passing 75 micron sieve measured by sedimentation method (IS:2386 Part 2).

2. Key Tests and Standards

3. Important Construction Parameters

• Aggregate grading as per specified limits for Granular Sub-Base (GSB).
• Compacted thickness as defined in Clause 402.3 Table 401.10.
• In-situ density and compaction degree (Clause 402.13).
• Temperature control for binder and mix critical for bituminous applications.

Detailed content not provided.

Moisture Susceptibility of Bituminous Mixtures (Clause 509.2)

Objective: Evaluate the resistance of compacted asphalt mixtures to moisture damage and the potential for stripping.

Procedure and Requirements:

• Specimens:

  • Produce six Marshall-compacted samples with air voids of 7.0 ± 0.5%.
  • Divide into two groups: three dry and three moisture-conditioned.

• Moisture Conditioning:

  1. Partially saturate specimens.
  2. Wrap in plastic and seal inside a bag with 10 ml water.
  3. Freeze at -18°C ± 3°C for at least 16 hours.
  4. Thaw specimens in a 60°C ± 1°C water bath for 24 hours.
  5. Condition in a 25°C ± 0.5°C water bath for 2 hours before testing.

• Indirect Tensile Strength Testing:

  • Conduct test at 25°C ± 0.5°C.
  • Load at 50 mm/min diametrically.
  • Measure specimen thickness (t) and diameter (d).

Calculation Formulas:

[ S_t = \frac{2000 \times P}{t \times d} \quad \text{(Tensile Strength in kPa)} ]

Where:

• (P) = Maximum load (Newtons)
• (t) = Thickness of specimen (mm)
• (d) = Diameter of specimen (mm)

[ TSR = \frac{S_2}{S_1} ]

Where:

• (S_1) = Average tensile strength of dry specimens (kPa)
• (S_2) = Average tensile strength of conditioned specimens (kPa)
• TSR = Tensile Strength Ratio (index of moisture resistance)

Interpretation:

• TSR near 1 indicates good moisture resistance.
• Lower TSR values suggest increased susceptibility to moisture damage and stripping.

Summary Table:

Routine Inspection and Testing Procedures (Clause 1000.6, IS:1786-2008)

• Scope: All steel reinforcement materials must undergo routine inspection and testing by manufacturers or suppliers in accordance with IS:1786-2008.
• Documentation: Maintain test records and certificates accessible for purchaser review.
• Compliance Certificates: Suppliers must provide certificates confirming test results on representative samples.
• Quality Assurance: Quality control personnel should verify certificates; if doubts arise, independent laboratory tests may be conducted.

Key Specifications and Tests for Steel Reinforcement (IS:1786-2008)

Routine Tests Include:

• Tensile tests (ultimate strength, yield strength, elongation)
• Bend test
• Dimensional verification (diameter, rib spacing)
• Chemical and mechanical properties certification

Inspection Process Flow

flowchart TD
    A[Steel Delivery] --> B[Manufacturer Routine Testing]
    B --> C{Tests Performed}
    C -->|Tensile| D[Ultimate Strength and Elongation]
    C -->|Bend Test| E[Crack-free Bending]
    C -->|Dimensional Check| F[Diameter and Rib Pitch Verification]
    B --> G[Issue Certification]
    G --> H[Quality Control Verification]
    H --> I{Issues?}
    I -- No --> J[Approval]
    I -- Yes --> K[Further Testing]

Environmental Safety Measures in Concreting as per MORD 21 and IS Codes:

1. Water Quality Requirements (Clause 2000.33 & IS 3025):

   • pH must be ≥ 6.
   • Organic solids ≤ 200 mg/L.
   • Inorganic solids ≤ 3000 mg/L.
   • Sulphates (SO4) ≤ 400 mg/L.
   • Chlorides ≤ 2000 mg/L for plain concrete.
   • Suspended solids ≤ 2000 mg/L.
   • Strength loss not exceeding 10% compared to distilled water cured cubes.
   • Initial setting time difference within ±30 minutes compared to control.

2. Temperature and Humidity Control (Clause 20.0):

   • Perform curing at 27 ± 2°C and 90% relative humidity.
   • Take precautions for concreting in hot and cold weather using admixtures and proper curing methods.

3. Formwork and Removal Procedures (Section 900):

   • Use mortar-tight, rigid formwork with release agents avoiding direct steel contact.
   • Minimum removal times at ambient temperatures above 10°C:
     • Walls and columns: 12–48 hours.
     • Slab soffits (with props): 3 days.
     • Props under slabs: 14 days.
     • Girder soffits (with props): 7 days.
     • Props under girders: 21 days.

4. Mix Design and Workability:

   • Follow IRC:44 and IS:10262 for mix proportions.
   • Maintain slump or compaction factor as specified.

Flexural Strength Formula of Concrete Beam (IS 516-1959)

[ f_r = \frac{3 W L}{2 B D^2} ]

Where:

• (f_r) = Flexural strength (kg/cm²)
• (W) = Breaking load (kg)
• (L) = Effective span length between supports (cm)
• (B) = Breadth of beam (cm)
• (D) = Depth of beam (cm)

Formwork Removal Time Summary (Ambient > 10°C)