Quality Assurance Handbook for Rural Roads, Volume II

Earthwork in Cutting – Key Formulas, Tables & Specifications (MORD 21 / IRC SP-11)

1. Material Tests (Clause 302.A)

2. Construction & Workmanship (Clause 302.B)

• Moisture Content Determination:
  • Oven Drying (IS 2720 Part 2)
  • Sand Bath, Infrared Lamp, Calcium Carbide methods
• In-situ Density / Degree of Compaction:
  • Sand Replacement Method
  • Core Cutter Method
  • Nuclear & Non-Nuclear Density Gauges
• Surface Checks:
  • Horizontal Alignment (Clause 302.10)
  • Surface Levels (Clause 302.11)
  • Surface Regularity (Clause 302.12)

3. Degree of Compaction Formula:

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

4. Surface Regularity Check (from Clause 1.5 IRC SP-11):

• Use a 1.5 m straight edge slid forward incrementally.
• Measure undulations with a wedge gauge.
• Count depressions exceeding specified limits.
• Mark locations of depressions.

5. Summary Table for Earthwork Testing

Key Specifications & Tests for Subgrade Construction (Clause 303, MORD 21)

A) Materials Testing:

B) Construction & Workmanship:

Important Formula: Degree of Compaction (%)

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

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

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

Summary Diagram of Subgrade Quality Control

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

Key Materials Testing Methods as per IS Code MORD 21

1. Aggregates Testing

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

2. Bitumen & Binder Tests

• Penetration Test (Clause 509.21): Measures hardness.
• Softening Point (R&B): Temperature at which bitumen softens.
• Ductility: Elongation before breaking.
• Elastic Recovery & Separation Tests: For modified bitumen (Clause 511).
• Viscosity at 150°C.
• Thin Film Oven Test: Aging characteristics.
• Rate of Spread of Binder & Mix (Clauses 503.6, 509.21).

3. Water Suitability for Construction

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

4. Cement & Lime Tests

• Setting Time (Initial & Final) (Clause 600.5).
• Soundness: Le Chatelier method (Clause 800.2).
• Compressive Strength (Clause 800.3).
• Purity of Lime as CaO (Clause 2000.17).

5. Concrete Testing

• 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).

Key Formulas and Specifications for Compaction & Moisture Content Tests (IS Code MORD 21)

1. Compaction Test Parameters:

• Weight of mould (W1)
• Weight of mould + compacted soil (W2)
• Weight of wet soil = W2 - W1
• Wet density (ρ_w) = Weight of wet soil / Volume of mould (V)
• Moisture content (W%) = (Weight of water / Weight of dry soil) × 100
• Dry density (ρ_d) = Wet density / (1 + W%)

2. Moisture Content Calculation:

[ 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 Values of Maximum Dry Density and Optimum Moisture Content (IS: 2720 Part 7)

5. Factors Affecting Compaction:

• Water Content: Dry density peaks

Key Specifications & Tests for Bituminous Binder Quality Assurance (per MORD 21):

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

• Measures hardness/consistency of bitumen.
• Penetration value: depth (0.1 mm) a needle penetrates under standard load, time, and temperature.
• Typical range: 40-60 (for paving grade bitumen).

2. Ring & Ball (R&B) Softening Point (Clause 507.8 / 504.2(b))

• Temperature at which bitumen softens.
• Important for temperature susceptibility.
• Typical softening point: 46-56°C for paving grade.

3. Ductility Test (Clause 504.1)

• Measures bitumen's ability to stretch without breaking.
• Standard ductility: ≥ 75 cm at 27°C.

4. Absolute Viscosity (Clause 507.5 / 502.14)

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

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

• Measures elasticity of modified bitumen.
• Typical minimum: 50%.

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

• Checks homogeneity of modified bitumen.

7. Bitumen Emulsion Tests (Clause 506.2.1)

• Viscosity (Saybolt Furol), Residue on 600 micron sieve, Storage Stability, Residue by Evaporation.

Summary Table: Bituminous Binder Tests

Viscosity Testing of Bitumen and Cutbacks (IS Code MORD 21, Clause 502.14)

1. Kinematic Viscosity of Cutback Bitumen at 60°C (Table 502.14.1)

Reference: IS 1206 (Part 3)

2. Determination of Absolute Viscosity by Cannon Manning Vacuum Capillary Viscometer

• Heat sample to 135 ± 5.5°C (max 60°C for tars/pitches, 90°C for bitumen).
• Charge viscometer to fill line ± 2 mm.
• Maintain vacuum at 30 ± 0.05 cm Hg.
• Measure flow time ( t ) (seconds) after 30 ± 5 min conditioning.
• Calculate absolute viscosity:

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

where
( K ) = calibration constant (Poise/s),
( t ) = flow time (s).

Reference: IS 1206 (Part 2)

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

• Equilibrate sample temperature (20–30 min depending on temp).
• Measure efflux time ( t ) between timing marks E and F.
• Calculate kinematic viscosity:

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

where
( C ) = calibration constant (cSt/s),
( t ) = efflux time (s).

4. Brookfield Viscometer

• Follow manufacturer instructions.
• Set test temperature with thermosel.
• Measure viscosity directly in Poise or mPa·s.

Summary Diagram: Viscosity Testing Workflow

flowchart TD
    A[Sample Preparation] --> B[Heat to Test Temperature]
    B --> C[Charge Vis

Concrete Pavement Construction & Testing — Key Points from MORD 21 (Clauses 2000.20 to 2000.32)

1. Concrete Mix Design & Materials

• Follow mix design as per IRC:44 / IS:10262.
• Use suitable water (Clause 2000.32).
• Use premoulded joint fillers and approved joint sealing compounds.
• Aggregate gradation & moisture content per Clause 400.

2. Pavement Thickness & Dimensions

• Thickness and width as per design; ensure straightness of side forms.
• Dowel bars: size, spacing, depth, and alignment per specifications.
• Transverse contraction joints: width and depth as specified.

3. Workability & Compaction

• Workability checked by slump or compaction factor.
• Use needle, screed, and plate vibrators for compaction.
• Hot/cold weather concreting precautions.

4. Testing: Flexural Strength of Concrete Beams (IS:516)

• Beam size: 10×10×50 cm
• Effective 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) = load at failure (kg)

• (L) = span length (cm)

• (B) = width (cm)

• (D) = depth (cm)

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

• Variation allowed: ±15% of average

5. Surface Regularity & Joint Alignment

• Measure surface regularity with straightedge or profilometer.
• Ensure joints are aligned and sealed properly.

6. Quality Control

• Trial length of 30m before full-scale work.
• Use measuring steel tape for dimensions.
• Concrete core density tests for compaction.

Summary Table: Flexural Strength Test Parameters

Rectangular Concrete Block Pavement (IS Code MORD 21 - Clause 1503)

Key Specifications & References:

• Materials:

  • Cement: IS 2000.13 to 2000.15
  • Fine & Coarse Aggregates: IS 400, 2000.20 to 2000.31
  • Flyash: IS 2000.12 to 2000.16
  • Water Suitability: IS 2000.32
  • Admixtures: IS 2000.19

• Block Manufacturing & Properties:

  • Method of manufacturing & compaction as per specifications
  • Block dimensions and thickness per Clause 1503.22
  • Compressive strength: IS 800.26
  • Joint width & laying pattern: Clause 1503.18 & 1503.7

• Subgrade & Subbase:

  • As per IS 303, 401

• Trial Length:

  • Performance evaluation as per Clause 1501.12

Important Checks & Controls:

Typical Block Dimensions & Strength (Example)

Formula for Pavement Thickness (General Guide)

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

Where:

• ( t ) = pavement thickness (mm)

Key Specifications & Formulas for Pipe Culverts and Vented Causeways (IS Code MORD 21)

1. Pipe Culverts

• Straightness Test (Clause 2000.42):
  Use a rigid straight edge gauge inside the pipe bore.

  • If both ends of the gauge contact the internal surface simultaneously at any 4 positions around circumference → pipe fails straightness.
  • Reverse gauge and check studs on edge Y similarly.
  • Reference: IS 458, IS 3597.

• Dimensions & Alignment:

  • Horizontal alignment and surface regularity per Clauses 301.9, 301.10, 301.11.
  • Measurement tools: levels, straight edges, measuring tapes.

2. Vented Causeways

• Generally designed as multiple small openings (pipes/boxes) to allow water passage.
• Follow earthwork and subgrade construction standards (Clauses 302, 303).
• Use Proctor density, CBR, moisture content tests (Clauses 302.3, 302.7, 302.8) to ensure embankment stability around causeways.

Important Test Methods & Parameters

Design Formulae (Typical for Pipe Culverts)

• Hydraulic Capacity:
  [ Q = A \times V ] Where:
  (Q) = Discharge (m³/s)
  (A) = Cross-sectional area of pipe (m²)

Detailed content not available.

Aggregate Quality & Deleterious Material Limits (MORD 21)

1. Limits of Deleterious Materials (Clause 2000.27.1 - Table 2000.27.1)

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

2. Key Tests & Specifications

3. Important Construction Parameters

• Grading of Aggregates: As per specified gradation limits for granular sub-base (GSB).
• Compacted Thickness: Refer Clause 402.3 Table 401.10.
• In-situ Density & Degree of Compaction: Clause 402.13.
• Temperature of Binder & Mix: Critical for bituminous mixes.
• **

Detailed content not available.

Water Sensitivity of Bituminous Mixtures (Clause 509.2)

Purpose:
Assess resistance of compacted asphalt mixtures to moisture damage and predict stripping susceptibility.

Key Steps & Specifications:

• Specimens:

  • Prepare 6 Marshall compacted specimens (air voids = 7.0 ± 0.5%).
  • Divide into 2 subsets: 3 dry, 3 moisture-conditioned.

• Moisture Conditioning:

  1. Saturate specimens partially.
  2. Wrap in plastic, seal in bag with 10 ml water.
  3. Freeze at -18ºC ± 3ºC for ≥16 hours.
  4. Thaw in 60ºC ± 1ºC water bath for 24 hours.
  5. Condition in 25ºC ± 0.5ºC water bath for 2 hours before testing.

• Indirect Tensile Strength Test:

  • Test at 25ºC ± 0.5ºC.
  • Load rate: 50 mm/min diametrically.
  • Measure thickness (t) and diameter (d).

Formulas:

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

• (P) = Maximum load (N)
• (t) = Specimen thickness (mm)
• (d) = Specimen diameter (mm)

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

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

Interpretation:

• TSR close to 1 → Good moisture resistance.
• Lower TSR → Higher susceptibility to moisture damage/stripping.

Summary Table:

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

• Scope: All steel reinforcement shall undergo routine inspection and testing by the manufacturer/supplier as per IS:1786-2008.
• Documentation: Test records and certificates must be maintained and available for purchaser inspection.
• Certificate of Compliance: For supplied materials, a certificate with test results on representative samples must be provided.
• Quality Control: Quality personnel should verify certificates; independent lab tests may be done if doubts arise.

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

Routine Testing Includes:

• Tensile Test (Ultimate strength, yield strength, elongation)
• Bend Test
• Dimensional checks (diameter, rib spacing)
• Certification of chemical and mechanical properties

Summary Table for Steel Inspection

flowchart TD
    A[Steel Material Delivery] --> B[Manufacturer Routine Testing]
    B --> C{Tests Conducted}
    C -->|Tensile Test| D[Tensile Strength, Elongation]
    C -->|Bend Test| E[No Cracks on Bending]
    C -->|Dimensional Check| F[Diameter & Rib Pitch]
    B --> G[Certification Issued]
    G --> H[Quality Control Verification]
    H --> I{Doubt?}
    I -->|No|

Environmental Precautions in Concreting (per MORD 21 & IS Codes):

1. Suitability of Water (Clause 2000.33 & IS 3025):

   • pH ≥ 6
   • Organic solids ≤ 200 mg/L
   • Inorganic solids ≤ 3000 mg/L
   • Sulphates (SO4) ≤ 400 mg/L
   • Chlorides ≤ 2000 mg/L (plain concrete)
   • Suspended matter ≤ 2000 mg/L
   • Strength loss ≤ 10% compared to distilled water cubes
   • Initial setting time difference ±30 min vs control

2. Temperature & Humidity Control (Clause 20.0):

   • Testing at 27 ± 2℃, RH = 90% to ensure curing environment
   • Hot/Cold weather concreting precautions (use admixtures, curing methods)

3. Formwork & Removal (Section 900):

   • Use mortar-tight, rigid forms with release agents avoiding steel contact
   • Removal times (Portland cement, ambient >10℃):
     • Walls/columns: 12-48 hrs
     • Slab soffits (props under): 3 days
     • Props under slabs: 14 days
     • Girder soffits (props under): 7 days
     • Props under girders: 21 days

4. Mix Design & Workability:

   • Follow IRC:44 / IS:10262 for mix proportions
   • Maintain slump/compaction factor as per requirements

Key Formula: Flexural Strength 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 length between supports (cm)
• ( B ) = breadth of beam (cm)
• ( D ) = depth of beam (cm)

Summary Table: Formwork Removal Time (Ambient >10℃)