Quality Assurance Handbook for Rural Roads, Volume I

Scope of MORD 20 (Volume II - Equipment and Procedures for Tests)

• Applicability: Specifies equipment, test procedures, and quality control for rural road construction materials.
• Key Parameters:
  • Paint properties (Clause 1002.3):
    • Weight (per 10 L mixed paint)
    • Drying time
    • Consistency
    • Dry thickness and consumption rate
    • As per relevant IS codes for paint types.
  • Soil-Aggregate Mixture Grading (Table 402.2-B):

    Sieve Size	% Passing by Weight
    10 mm	100
    4.75 mm	80 - 100
    2.36 mm	50 - 80
    1.18 mm	40 - 65
    300 micron	20 - 40
    75 micron	10 - 25

• Fabrication: Requires shop drawings and work programme before starting structural steel fabrication.

Important Abbreviations:

• OMC: Optimum Moisture Content
• UCS: Unconfined Compressive Strength
• WMM: Wet Mix Macadam
• MPa: Mega Pascal

This scope ensures standardized testing and quality assurance in rural road materials and construction.

Material Specifications & Quality Control Tests (MORD 20)

Key Tests Prior to Construction

Important Notes:

• All materials must comply with relevant IS codes.
• Tests ensure durability, strength, and compatibility.
• Approval by the Executive Engineer (EE) is mandatory before starting construction.

Quick Reference: Binder Viscosity Test (IS:8887)

[ \text{Viscosity} = \frac{\text{Torque} \times \text{Constant}}{\text{Temperature correction}} ]

(Refer IS:8887 Annexure-II for detailed procedure)

flowchart TD
    A[

Key Specifications for Reinforced Concrete Construction (MORD 20)

1. Grades of Concrete (Table 800.1)

• Use design mix for grades > M20.
• Nominal mixes (M20, M25) allowed for small works with supervision.

2. Minimum Cement Content & Water-Cement Ratio (Table 800.2)

• Cement includes blended materials (fly ash, slag per IS:1489, IS:455).
• Adhere strictly to exposure conditions for durability.

3. Additional Notes

• Compressive strength as per IS 516.
• Joints and curing details per clauses 301.5, 401.3.
• Quality control essential for nominal mixes.

Basic Formula for Concrete Mix Design (Simplified)

[ \text{Water-Cement Ratio} = \frac{\text{Weight of Water}}{\text{Weight of Cement}} ]

[ \text{Characteristic Strength} = f_{ck} \quad \text{(MPa at 28 days)} ]

flowchart TD
    A[Concrete Grade] --> B{Select Mix Type}
    B -->|Nominal Mix| C[M15, M20, M25]
    B -->|Design Mix| D[M30, M40, M45]
    D --> E[Check Exposure Conditions]
    E --> F[Determine Cement Content & W/C Ratio]
    F --> G[Produce Concrete]
    G --> H[Quality Control & Testing

Prestressed Concrete Construction (PSC) - Key Points from MORD 20

1. PSC Girder and Composite RCC Slab (Clause 1400.1 II.A4)

• Types: Precast or cast-in-situ, post-tensioned or pretensioned girders.
• Concreting: Cast top flange, web, and bottom flange in a single operation without construction joints.
• Deck slab: Cast near expansion joints with reinforcements and embedments; rough finish before hardening.
• Alignment: Ensure correct bearing alignment and setting as per drawings.
• Construction sequence: Follow method statements for girder shifting and placement.

2. PSC Box Girders

• Provide simply supported or continuous box girders.
• Max one construction joint in the web below fillet between deck slab and web.
• Similar deck slab casting and finishing as PSC girders.

3. Voided Slabs (Prestressed or Reinforced)

• Tie down void formers to prevent flotation during concreting.
• Ensure concrete fully flows below void formers.

4. Composite Construction (RCC slab on Steel Girder)

• Use shear connectors for composite action.
• Minimum 28 days curing before traffic.
• Provide 150 mm x 150 mm haunches between steel girder top and slab soffit.
• Protective coatings as per IS:1477.

Relevant Tables & Specifications

Summary Formula: Prestressing Force (P)

[ P = \frac{M}{e} + \sigma_c \times A_c ]

Where:

• (M) = Moment at section
• (e) = Eccentricity of prestressing force
• (\sigma_c) = Allowable compressive stress in concrete
• (A_c) = Cross-sectional area of concrete

Cast In-Place Voided Slabs (IS Code MORD 20 - Clause 1400.1 III A6)

Key Specifications:

• Provide either Reinforced Concrete (RC) or Prestressed Concrete (PSC) voided slabs as specified.
• Tie down void formers securely to prevent flotation during concreting.
• Ensure concrete fully flows beneath void formers for proper compaction.
• Cast slabs in one continuous operation where possible, avoiding construction joints near voids.
• Finish slab surface rough but true to lines and levels before concrete hardening.
• Provide curing as per Section 800 to ensure durability.

Important Construction Notes:

Aggregate Gradation for Concrete (Table 1)

Concrete Placement and Compaction

• Use mechanical mixers ≥ 0.2 m³ capacity.
• Slump: 30 mm ± 10 mm (≤ 20 mm for hill roads).
• Place concrete continuously, level with rakes/shovels.
• Compact thoroughly using vibrators, especially below void formers.

Diagram: Concrete Flow Around Voids

flowchart LR
    A[Concrete Pouring] --> B[Concrete Flows Over Voids]
    B --> C[Concrete Fills Space Below Voids]
    C --> D[Proper Compaction Ensured]
    D --> E[Void Formers Tied Down Preventing Flotation]

Summary: Tie void formers securely, ensure concrete fully encapsulates void

Composite Type Construction (Clause 1400.1 - A7)

Key Specifications:

• Composite superstructure = Longitudinal steel girders + RCC solid slab decking (for simply supported bridges only).
• Shear connectors must be provided to ensure composite action (as per drawings).
• No traffic allowed before 28 days of deck concreting for effective composite action.
• Provide 150 mm × 150 mm haunches between steel girder top and slab soffit.
  • Haunch sides located outside a 45° line from the base edge of connectors.
• Steel components must be protected against corrosion:
  • Minimum 3 coats of paint or metal coating + 2 coats paint.
  • Follow IS:1477 for painting and protective coating.

Important Tables & Values for Concrete (From Clause 800.1)

• Use design mix for grades > M20.
• Cement content and w/c ratio depend on exposure severity.

Shear Connector & Haunch Location (Conceptual Diagram)

flowchart LR
    SteelGirder[Steel Girder Top Flange]
    Haunch[150x150 mm Haunch]
    RCCSlab[RCC Deck Slab]
    Connector[Shear Connectors]

    SteelGirder --> Haunch --> RCCSlab
    Connector -. Ensures Composite Action .-> SteelGirder
    Connector -. Ensures Composite Action .-> RCCSlab

    style Haunch fill:#f9f,stroke:#333,stroke-width:2px

Summary: Composite construction uses steel girders and RCC slab with shear connectors for load transfer. Proper curing (28 days) and corrosion protection are critical. Haunches ensure proper load distribution and connector positioning. Use concrete grades and mix as per exposure condition and IS guidelines.

Bituminous Concrete Mix Design & Laying (IS Code MORD 20)

1. Mix Design Requirements (Table 509.4)

VMA Minimum % for 9.5 mm nominal size:

• Hot Climate: 14%
• Cold Climate: 15-16%

2. Aggregate Grading for Semi-Dense Bituminous Concrete (Table 509.3)

• Minimum Bitumen Content: 5% (adjusted for specific gravity and climate)
• Binder: Viscosity Grade or Modified Bitumen

3. Marshall Mix Design Key Formulas

• Bulk Specific Gravity (Gmb):
  [ Gmb = \frac{\text{Mass of specimen in air}}{\text{Volume of specimen}} ]

Key Formulas & Specifications for Soil Stabilization and Cold Mixes (MORD 20)

1. Soil Stabilization

• Cement Content Guidelines:

• Strength Requirements:

• Compaction:
  • Stabilized subgrade: ≥ 98% of max dry density (IS 2720 Part 7)
  • Stabilized sub-base/base: ≥ 100% of max dry density

2. Cold Mix Bituminous Macadam (BM)

• Aggregate Requirements (Table A-1):

• Aggregate Gradation for 50 mm BM (Table A-2):

Use of Local Materials in Road Construction (MORD 20, Clause 408)

Key Specifications & Processing Techniques

Use in Pavement Layers (Table 408.2)

Tolerances & Quality Control

• Horizontal Alignment: ±30 mm (plain/rolling), ±50 mm (hilly)
• Surface Levels:
  • Sub-base: +10 mm / -20 mm
  • Base & Surface: ±10 mm (grid 10m x 2.5m)
• Surface Regularity:
  • Sub-base: Max 12 mm (longitudinal), 10 mm (cross) deviation from 3 m straight edge
  • Base & Surface: Max 12 mm (longitudinal), 8 mm (cross)

Do's & Don'ts Summary

Do's

• Conduct thorough field survey of local materials & industrial wastes.
• Select stabilization based on soil properties.
• Use two-stage stabilization for expansive clays.
• Test industrial wastes before use.

**Don't

Installation of Bearings and Expansion Joints: Key Points from MORD 20

Bearings Installation (Clauses 1400 & 1402.5)

• Manufacturing:

  • Main bearing components must be monolithic cast/forged (no welding).
  • Mild steel parts machined from single pieces, free from laminations.

• Positioning & Protection:

  • Bearings located to avoid dirt accumulation and water ingress.
  • Bearings not dismantled post-manufacture unless expert supervised.

• Bedding Material:

  • Use cementitious or chemical resin mortar/grout, full bearing area coverage, no voids or hard spots.
  • Thickness of mortar pads ≤ 12 mm for level seating.

• Fixing:

  • Anchor bearings firmly using templates and fill recesses with load-bearing material.
  • Ensure no mismatch in bolt holes, tighten fasteners uniformly.

• Special Notes:

  • No MS-on-MS sliding; use stainless steel or PTFE sliding surfaces.
  • Provide guides for rocker/roller bearings in seismic zones IV & V.
  • Bearings placed perpendicular to bridge axis for skew < 20°; follow drawings for larger skew.

Expansion Joints Installation (Clause 1403 & 1400.2 Table)

• General:

  • Install under manufacturer's supervision with their manual.
  • Prepare recess dimensions per manufacturer’s design.
  • Lay road surfacing before joint installation; remove wearing coat over recess before fitting.

• Types & Reference Clauses:

• Steel Bearings Expansion Joint Seal:
  • Steel angle nosing anchored with rebars/plates.
  • Preformed chloroprene/closed-cell foam seal allowing ±40 mm horizontal, ±3 mm vertical movement.

Summary Diagram: Bearing Installation Flow

flowchart TD
    A[Receive Bearings] --> B[Store under cover]
    B -->

Detailed content not available.

Field Quality Control and Inspections (MORD 20)

Key Specifications & Tests

1. Pre-Construction Quality Control (Table A-4)

2. During Construction (Table 1502.5)

Important Notes:

• Sand Replacement Method (IS:2720-28) is used for in-situ density.
• Workability includes zero slump test for Roller Compacted Concrete Pavement (RCCP).
• Regular checks ensure compliance with mix design and construction quality.

flowchart TD
    A[Pre-Construction Tests] --> B[Binder Quality Tests]
    A --> C[Aggregate Quality Tests]
    D[During Construction Tests] --> E[Gradation & Moisture]
    D --> F[Batching & Mixing]
    D

Environmental and Weather Considerations (IS Code MORD 20)

1. Modified Bitumen Properties (Clause 511.2, Table 511.2)

Bitumen specs vary with highest mean air temperature:

*Note: Higher softening point required for hotter climates.

2. Embankment & Subgrade Requirements (Clause 14.4 & Table 301.3)

• Density:
  • Embankment: ≥ 98% Standard Proctor Density (IS:2720 Part 7)
  • Sub-grade (top 300mm): 100% Standard Proctor Density
• Compaction of expansive clays:
  • Subgrade & 500 mm below: Not allowed
  • Remaining embankment: 90-95%

3. Surface Tolerances (Table 301.2)

4. Soil-Aggreg

Quality Assurance for New Technologies (MORD 20)

Referencing Clause 800.14 and Table 800.14, along with the Quality Assurance Handbook for Rural Roads:

Key Quality Control Tests Prior to Construction (Table A-4)

Specifications & Guidelines

• Binder tests ensure consistency and compatibility with aggregates.
• Aggregate tests ensure durability, shape, and cleanliness.
• Quality Assurance Handbook Volumes I & II provide updated procedures, permissible limits, and new test methods for emerging materials and technologies.

Summary Diagram of QA Process

flowchart TD
    A[New Technology Introduction] --> B[Material Testing]
    B --> C{Binder Quality Tests}
    B --> D{Aggregate Quality Tests}
    C --> E[Viscosity, Stability, Residue]
    D --> F[Impact, Flakiness, Sand Eq., Absorption]
    E & F --> G[Compliance Check]
    G --> H[Approval for Construction]

Ensure all tests comply with latest QA Handbook and IS standards for reliable performance of new materials and technologies.

MORD 20 - Appendices and Glossary Key Points

Glossary (Abbreviations from Volume-II)

Key Specifications for Tests (Clause 5.1 & 5.2)

• Tests Prior to Construction: Refer to Appendix Part II, Table A-4.
• Tests During Construction: Refer to Appendix Part II, Table A-5.

Notes:

• Detailed test procedures and equipment are specified in the appendices.
• Use the abbreviations for quick reference in test reports and documentation.

flowchart LR
    A[Start: Construction Project] --> B{Testing Phase}
    B --> C[Pre-construction Tests (Table A-4)]
    B --> D[During Construction Tests (Table A-5)]
    C --> E[Proceed if Tests Passed]
    D --> E
    E --> F[Construction Continues]

For exact test methods and values, consult the respective Tables A-4 and A-5 in Appendix Part II of MORD 20 Volume II.