Specifications for Open-Graded Friction Course

IRC 129 - Introduction: Key Specifications & Formulas

IRC 129 covers Open Graded Friction Course (OGFC) design, production, and testing. The Introduction outlines essential test procedures and equipment for quality control.

Key Test Procedures & Formulas

1. Drain-down Test (Wire Basket Method)

• Purpose: Measure binder drain down at production and +10°C.
• Formula:

[ \text{Drain-down (%)} = \frac{W_A - W_3}{W_2 - W_1} \times 100 ]

Where:

• (W_1) = Mass of empty wire basket (g)
• (W_2) = Mass of basket + sample (g)
• (W_3) = Mass of empty catch plate (g)
• (W_A) = Mass of catch plate + drained material (g)

2. Schellenberg Binder Drainage Test

• Similar principle using a glass beaker at 170°C for 1 hour.
• Drain-down % = (\frac{W_2 - W_3}{W_2 - W_1} \times 100)

3. ASTM C29 - Bulk Density & Voids in Aggregate

• Unit Weight Calculation:

[ Y_s = \frac{G - T}{V} ]

Where:

• (Y_s) = Unit weight of aggregate (kg/m³)
• (G) = Mass of measure + aggregate (kg)
• (T) = Mass of empty measure (kg)
• (V) = Volume of measure (m³)

4. ASTM D2041 - Theoretical Maximum Specific Gravity (Gmm)

• Used to calculate air voids and bitumen absorption.
• Vacuum method to remove entrapped air.
• Target for compaction control.

Equipment Highlights

• Wire basket with 6.3 mm sieve cloth (±10% dimensions)
• Oven for heating samples
• Balance readable to 0.1 g
• 10 L cylindrical metal measure for aggregate density

flowchart TD
    A[Mix Sample] --> B[Wire Basket]
    B --> C[Oven Heating @ Production Temp]
    C --> D[Drain

IRC 129 - Scope: Key Specifications & Test Methods Summary

Scope (Clause 2):
Covers Open Graded Friction Course (OGFC) mix design, production, placement, compaction, and quality controls for bituminous pavements ensuring quick drainage and durability.

Key Test Methods & Formulas:

1. Drain-down Test (Wire Basket Method)

• Purpose: Measure binder drain down at production and +10°C.

• Formula: [ \text{Drain-down %} = \frac{W_A - W_3}{W_2 - W_1} \times 100 ]

  • (W_1) = Mass of empty wire basket (g)
  • (W_2) = Mass of basket + sample (g)
  • (W_3) = Mass of empty catch plate (g)
  • (W_A) = Mass of catch plate + drained material (g)

• Sample: 1200 ± 200 g mix, oven at test temperature for 1 hour.

2. Schellenberg Binder Drainage Test

• Measures binder drain down by heating ~1 kg mix in a glass beaker at 170°C for 1 hour.
• Drain-down %: [ \frac{W_2 - W_3}{W_2 - W_1} \times 100 ]
  • (W_1): Empty beaker weight
  • (W_2): Beaker + mix weight
  • (W_3): Beaker weight after draining

3. ASTM C29 - Bulk Density & Voids in Aggregate

• Unit Weight Calculation: [ Y_s = \frac{G - T}{V} ]

  • (Y_s): Unit weight (kg/m³)
  • (G): Mass of measure + aggregate (kg)
  • (T): Mass of empty measure (kg)
  • (V): Volume of measure (m³)

• Used for OGFC mix design voids calculation.

4. ASTM D2041 - Theoretical Maximum Specific Gravity (Gmm)

• Determines voidless density of bituminous mix at 25

IRC 129 Key Formulas, Tables & Specifications for Materials

1. Coarse Aggregate Requirements (Clause 4.75, Table 1)

2. Drain-down Test (Clause 6.3 & Annex C)

[ \text{Drain-down %} = \frac{W_2 - W_1}{W_2 - W_3} \times 100 ]

• (W_1): Empty wire basket mass (g)
• (W_2): Basket + sample mass (g)
• (W_3): Empty catch plate mass (g)
• (W_A): Catch plate + drained material mass (g)

Test at production temp and 10°C higher, average results.

3. Bulk Density of Aggregate (ASTM C29)

[ Y_s = \frac{G - T}{V} ]

• (Y_s): Unit weight (kg/m³)
• (G): Mass of measure + aggregate (kg)
• (T): Mass of measure (kg)
• (V): Volume of measure (m³)

4. Theoretical Maximum Specific Gravity (ASTM D2041)

Used to calculate air voids and bitumen absorption.

• Sample submerged in water

OGFC Mix Design per IRC 129 & ASTM D7064M-08(2013)

Key Specifications (Table 3)

Aggregate Gradation (Table 2)

Voids in Coarse Aggregate (VCA) Calculation (Clause 9.5)

[ VCA_{DRC} = \frac{G_{ca} \times Y_w - Y_s}{G_{ca} \times Y_w} \times 100 ]

• (G_{ca}) = Bulk specific gravity of coarse aggregate
• (Y_w) = Unit weight of water (998 kg/m³)
• (Y_s) = Unit weight of dry-rodded coarse aggregate (kg/m³)

Compaction

• Use Marshall compaction with 25 blows per side (Asphalt Institute MS-2).

Additional Notes

• Use cellulose fibres to prevent drain down; protect fibres from moisture before mixing.
• Nominal maximum aggregate size (NMAS) = 9.5 mm.
• Nominal layer thickness = 25 mm.

flowchart TD
    A[Aggregate Gradation] --> B[Mixing with Bitumen ≥5.5%]
    B --> C[Add Cellulose Fibres ≥0.3%]
    C --> D[Marshall Compaction (25 Blows/Side)]
    D --> E[Check Air Voids 18-22%]
    E --> F[

IRC 129: OGFC Production Key Points

1. Mixing Specifications

• Batch Plant:
  • Add fibre directly into the weigh hopper above the pugmill.
  • Increase dry mixing time by 5–10 seconds to ensure uniform fibre dispersion.
  • Increase wet mixing time by at least 5 seconds.
• Drum Mix Plant:
  • Use a separate fibre feeding system for uniform fibre introduction.
  • Fibre addition rate must not reduce normal production.
  • No fibre should be visible in baghouse fines.

2. Laboratory Permeability (Clause 4.11)

• Permeability test is optional.
• Recommended permeability: > 100 m/day for compacted OGFC specimens.

3. Fibre Requirements (Clause 3.4.2)

• Submit fibre manufacturer's latest test data with job-mix formula.
• Protect cellulose fibres from moisture and contamination before mixing.

Typical OGFC Mix Design Parameters (General Reference)

Mixing Time Adjustment Summary

flowchart LR
    A[Aggregate + Fibre] --> B[Dry Mixing (5-10s extra)]
    B --> C[Add Bitumen]
    C --> D[Wet Mixing (+5s)]
    D --> E[Compaction & Placement]

This ensures uniform fibre distribution and optimum OGFC performance.

OGFC Placement and Compaction - Key Points from IRC 129

1. Aggregate Gradation (Table 2):

• Nominal Maximum Aggregate Size (NMAS): 9.5 mm
• Nominal Layer Thickness: 25 mm

2. Mix Design Requirements (Table 3):

3. Voids in Coarse Aggregate (VCA) Calculation:

[ VCA_{DRC} = \left(1 - \frac{Y_s}{G_{ca} \times Y_w}\right) \times 100 ]

Where:

• (VCA_{DRC}) = Voids in coarse aggregate in dry rodded condition (%)
• (G_{ca}) = Bulk specific gravity of coarse aggregate
• (Y_w) = Unit weight of water = 998 kg/m³
• (Y_s) = Unit weight of coarse aggregate in dry rodded condition (kg/m³)

4. Placement & Compaction Notes:

• Ensure uniform fibre dispersion by adequate dry and wet mixing times (dry mixing increased by 5-10 sec, wet by at least 5 sec).
• Compaction must maintain high air voids (18-22%) to ensure permeability.
• Laboratory permeability test is optional but recommended permeability > 100 m/day.

flowchart TD
    A[Aggregate Preparation] --> B[Dry Mixing with Fibres]
    B --> C[Wet

Controls in IRC 129 (Clause 7 & Table 4)

Key Tests & Frequencies for OGFC Quality Control:

Important Formulas:

Drain-down (%) (ASTM D 6390):

[ \text{Drain-down} = \frac{W_A - W_3}{W_2 - W_1} \times 100 ]

• (W_1) = Mass of empty wire basket (g)
• (W_2) = Mass of basket + sample (g)
• (W_3) = Mass of empty catch plate (g)
• (W_A) = Mass of catch plate + drained material (g)

Unit Weight of Coarse Aggregate (ASTM C 29):

[ Y_s = \frac{G - T}{V} ]

• (Y_s) = Unit weight (kg/m³)
• (G) = Mass of measure + aggregate (kg)
• (T) = Mass of measure (

IRC 129 - Trial/Experimental Section Key Points

1. Drain-Down Test (Clause 6.3 & Annex B)

• Wire Basket Dimensions: Fig. 8, with ±10% tolerance; made with 6.3 mm sieve cloth.

• Sample: 1200 ± 200 g fresh hot mix.

• Procedure:

  • Weigh empty basket (W1), basket + sample (W2), empty catch plate (W3).
  • Heat basket + sample at production temp and at +10°C for 1 hr.
  • Weigh catch plate + drained material (WA).

• Drain-down % formula:

  [ \text{Drain-down} (%) = \frac{(W_A - W_3)}{(W_2 - W_1)} \times 100 ]

2. Schellenberg Binder Drainage Test (Annex C)

• Use 850 ml glass beaker.

• Heat mix at 170 ± 1°C for 1 hr.

• Drain-down %:

  [ \text{Drain-down} (%) = \frac{W_2 - W_3}{W_2 - W_1} \times 100 ]

3. Bulk Density & Voids in Aggregate (ASTM C29 - Annex D)

• Use 10 L cylindrical measure.

• Dry-rodded unit weight:

  [ Y_s = \frac{G - T}{V} ]

  where (G) = mass of measure + aggregate, (T) = mass of measure, (V) = volume.

4. Theoretical Maximum Specific Gravity (ASTM D2041 - Annex E)

• Determines Gmm at 25°C for air voids and compaction.
• Vacuum vessel used to remove air bubbles.
• Used for mix design and quality control.

Summary Table of Key Tests

Key Specifications & Schematic Guidance for OGFC Placement (IRC 129-2019):

1. Purpose of OGFC

• Facilitates quick drainage of water through the pavement surface.
• Reduces hydroplaning and improves skid resistance.

2. Schematic Sketch Highlights (Annex A)

• OGFC placed over impermeable base (Dense Asphalt or Cement Concrete).
• Drainage via longitudinal and transverse slopes directing water to collecting pipes or central verges.
• Typical layers:
  • OGFC surface course
  • Tack coat (CRMB)
  • Dense asphalt base or concrete deck
• On bridges, OGFC is laid over cement concrete with proper drainage structures.

3. Quality Control Tests (Table 4)

4. Drain-Down Test (ASTM D 6390) - Annex B

• Measures binder drain-down at elevated temperatures.
• Sample held in wire basket at 120-175°C for 1 hour.
• Drain-down % = (Mass of drained binder / Mass of total mix) × 100.

Visual Summary of OGFC Drainage System

flowchart TB
    OGFC_Surface["OGFC Surface Course"]
    Tack_Coat["Tack Coat (CRMB)"]
    Base["Dense Asphalt Base / Concrete"]
    Drainage["Longitudinal & Transverse Drainage"]
    Collecting_Pipe["Collecting Pipe / Central Verge"]

    OGFC_Surface --> Tack_Coat --> Base
    Base --> Drainage --> Collecting_Pipe

Summary:

• OGFC should be placed on

Outline of ASTM D 6390 - Drain-Down Characteristics (per IRC:129 Annex B)

A. Scope

• Measures drain-down (%) of uncompacted asphalt mix at elevated temps (120-175°C).
• Applicable mainly to Open-Graded Friction Course (OGFC) mixes.

B. Equipment

• Forced draft oven (±2°C control)
• Wire basket (6.3 mm sieve cloth, ~108 mm dia.)
• Catch plate (known mass)
• Balance (0.1 g readability)

C. Procedure

1. Weigh empty basket (W1).
2. Place 1200 ± 200 g of hot mix loosely in basket; weigh basket + mix (W2).
3. Weigh empty catch plate (W3).
4. Hang basket in oven at test temp for 1 hour ± 5 min; catch plate below.
5. Cool and weigh catch plate + drained material (WA).
6. Calculate drain-down:

[ \text{Drain-down} (%) = \frac{(W_A - W_3)}{(W_2 - W_1)} \times 100 ]

7. Test duplicates at production temp and 10°C higher; average results.
8. Max allowable drain-down: 0.30% (increase fibers if failed).

Key Dimensions (Wire Basket)

• Diameter: 108 mm (±10%)
• Mesh: 6.3 mm sieve cloth

Additional Notes

• ASTM D 6390 complements Schellenberg Binder Drainage Test (Annex C).
• Drain-down test ensures mix stability during production & transport.
• Critical for OGFC to prevent binder runoff and ensure pavement durability.

flowchart TD
    A[Prepare Hot Asphalt Mix] --> B[Weigh Basket (W1)]
    B --> C[Place Mix in Basket & Weigh (W2)]
    C --> D[Weigh Empty Catch Plate (W3)]
    D --> E[Hang Basket in Oven (1 hr)]
    E --> F[Cool & Weigh Catch Plate + Drained Material (WA)]
    F --> G[Calculate Drain-down %]

This concise outline helps ensure compliance with IRC:129 requirements for drain-down testing of open-graded asphalt mixes.

Outline of The Schellenberg Binder Drainage Test (IRC:129-2019 Annex C)

This test evaluates binder drain-down in loose asphalt mixes at elevated temperatures.

Equipment & Materials

• 850 ml glass beaker (~98 mm diameter × 136 mm height)
• Oven maintained at 170°C ± 1°C
• Balance readable to 0.1 g

Procedure

1. Weigh empty beaker: ( W_1 ) (g)
2. Immediately pour ~1 kg hot mix into beaker at anticipated field mixing temperature.
3. Weigh beaker + mix: ( W_2 ) (g)
4. Cover beaker and place in oven at 170°C for 1 hour ± 1 minute.
5. Remove beaker, empty mix without shaking/vibration.
6. Weigh empty beaker again: ( W_3 ) (g)

Calculation

[ \text{Drain-down} , (%) = \frac{W_2 - W_1}{W_2 - W_3} \times 100 ]

• Numerator: binder lost by drainage
• Denominator: mass of mix deposited

Acceptance Criteria

• Drain-down should be ≤ 0.30% at production temperature.
• If exceeded, increase fibre content to reduce drain-down.

Visual Summary (Mermaid.js)

flowchart TD
    A[Weigh empty beaker (W1)]
    B[Pour ~1kg hot mix, weigh (W2)]
    C[Cover beaker, oven at 170°C for 1 hr]
    D[Remove & empty beaker]
    E[Weigh empty beaker again (W3)]
    F[Calculate Drain-down %]

    A --> B --> C --> D --> E --> F

This test complements ASTM D6390 and is critical for ensuring OGFC mix stability during production and placement.

ASTM C 29 - Bulk Density and Voids in Aggregate (Dry-Rodded Method)

Key Equipment:

• Cylindrical metal measure: ~10 L capacity, height ≈ diameter
• Tamping rod: 16 mm diameter, ~600 mm length, hemispherical tip
• Balance: Accurate to 0.1% of test load
• Plate glass: ≥6 mm thick, 25 mm larger than measure diameter

Procedure Summary:

1. Calibrate volume (V): Fill measure with water, weigh, and calculate volume: [ V = \frac{\text{Mass of water}}{\text{Density of water (kg/m}^3)} ]
2. Fill measure with aggregate loosely, then rod 25 times with tamping rod.
3. Weigh measure + aggregate (G) and measure alone (T).
4. Calculate dry-rodded unit weight (Ys): [ Y_s = \frac{G - T}{V} \quad \text{(kg/m}^3) ]

Calculate Voids in Coarse Aggregate (VCA):

[ VCA_{DRC} = \frac{G_{ca} \times Y_w - Y_s}{G_{ca} \times Y_w} \times 100 ]

• (G_{ca}) = Bulk specific gravity of coarse aggregate
• (Y_w) = Unit weight of water (998 kg/m³)
• (Y_s) = Dry rodded unit weight (kg/m³)

Relevant Tables:

ASTM D 2041: Theoretical Maximum Specific Gravity (Gmm) & Density of Bituminous Mix

Purpose:

• Calculate air voids in compacted mixes
• Determine bitumen absorption
• Set compaction targets

Equipment

• Vacuum bowl (180-260 mm diameter, ≥160 mm height) with vacuum line & gasket
• Vacuum flask (~4000 ml) with stopper & vacuum line
• Balance (readable to 0.1 g)
• Water bath at 25 ± 1°C

Procedure Summary

1. Place loose mix sample in tared vacuum container.
2. Add water to immerse sample fully.
3. Apply vacuum gradually to 3.7 ± 0.3 kPa for 15 ± 2 min with agitation.
4. Release vacuum slowly.
5. Weigh sample and container either:
   • Underwater (mass = C) or
   • In air (mass = E)
6. Record dry sample mass in air = A, container mass in water = B, container + sample in water = C, container + sample in air = E.

Key Formulas

Method	Formula	Variables
Underwater Weighing		A = dry sample mass (g) <br> B = bowl mass underwater (g) <br> C = bowl + sample mass underwater (g)
In Air (Bowl)		A = dry sample mass (g) <br> D = bowl + lid + water mass (g) <br> E = bowl + lid + sample + water mass (g)
In Air (Flask)	Same as Bowl method with flask

Cantabro Abrasion Loss Test for OGFC (IRC 129)

A. Test Principle

• Measures abrasion loss (%) of compacted OGFC specimens in a Los Angeles abrasion machine (no steel balls).
• Indicates durability and resistance to raveling.

B. Equipment

• Los Angeles Abrasion Machine (30-33 rpm)
• Balance accurate to 0.1 g
• Collection plates

C. Specimen Preparation

• OGFC Marshall specimens compacted with 25 blows/face
• Oven cure at 60°C for 168 hours (7 days)
• Cool to 25°C and store 5 hours before testing

D. Test Procedure

1. Weigh specimen before test: P₁ (g)
2. Place specimen in the abrasion machine; rotate for 300 revolutions at 30-33 rpm
3. Weigh specimen after test: P₂ (g)
4. Calculate Cantabro Abrasion Loss (%):

[ \text{Abrasion Loss } (P) = \frac{P_1 - P_2}{P_1} \times 100 ]

E. Acceptance Criteria

F. Key Mix Requirements for OGFC (Table 3)

G. Notes

• Minimum 5 specimens each for aged and unaged tests.
• Aging: Oven at 60°C for 168 hours.
• The test is per IS:2386 (Part IV) for the abrasion machine.

flowchart TD
    A[Prepare OGFC Specimens] --> B[Weigh Specimen (P1)]
    B --> C[Rotate in LA Machine (300 rev,

Key Formulas and Specifications from IRC 129 (OGFC Mix Design & Testing)

1. Drain-down Test (Wire Basket Method)

• Sample: 1200 ± 200 g hot mix in 6.3 mm sieve wire basket (Fig. 8)
• Test temperatures: Plant production temp & +10°C
• Drain-down (%) calculation:

[ \text{Drain-down (%)} = \frac{W_A - W_3}{W_2 - W_1} \times 100 ]

Where:

• (W_1) = Mass of empty wire basket (g)
• (W_2) = Mass of basket + sample (g)
• (W_3) = Mass of empty catch plate (g)
• (W_A) = Mass of catch plate + drained material (g)

2. Schellenberg Binder Drainage Test

• Use 850 ml glass beaker (~98 mm dia × 136 mm height)
• Heat at 170 ± 1°C for 1 hour
• Drain-down (%) = (\frac{W_2 - W_1}{W_2 - W_1} \times 100) (similar concept)

3. Bulk Density & Voids in Aggregate (ASTM C 29)

• Unit weight (dry rodded):

[ Y_s = \frac{G - T}{V} ]

Where:

• (Y_s) = Unit weight of aggregate (kg/m³)
• (G) = Mass of measure + aggregate (kg)
• (T) = Mass of empty measure (kg)
• (V) = Volume of measure (m³)

4. Theoretical Maximum Specific Gravity (Gmm) (ASTM D 2041)

• Used for air voids calculation and mix design control
• Vacuum method removes entrapped air for voidless density
• Gmm at 25°C used as target for compaction

5. Quality Control Tests Frequency (Table 4, Clause 7.4.1)

• Controls on materials and mix during execution
• Minimum frequency per test ensures compliance

Summary Diagram: Drain-down Test Setup