Code of Practice for Construction of Jack-Arch Type of Bult-up Floor or Roof

IS 2118: Scope & Key Specifications

• Scope:
  IS 2118 covers materials and methods for bitumen and bituminous materials used in construction, including jack-arch construction.

• Key Specifications:

  • Crude Oil for Jack-Arch Construction (Appendix A):
    • Specific gravity: 0.930 to 0.940 at 25°C (Clause A-2.1)
  • Rounding off results:
    • Follow IS 2-1960 for rounding test/analysis values, maintaining the same number of significant digits as specified (Clause 0.5).

• Additional Notes:

  • Solubility and other physical properties detailed in Appendix A (Clause 3.5) are critical for quality control.

This ensures material consistency and compliance with IS 2118 standards for bituminous materials.

IS 2118: Definitions & Terminology - Key Points

• Clause 2.0: Defines terms used in the standard for clarity and uniformity.

• Clause 2.5 (Lime): For lime-related definitions, refer to IS 6508-1972 (Building Lime).

• Clause 0.5 (Rounding Off): Test or analysis results must be rounded per IS 2-1960, keeping the same significant digits as specified values.

Important Considerations for Design & Construction (Clause 4.1)

• Surface area & loading conditions: Essential for structural design.

• Supporting elements: Type and arrangement restrictions.

• Leveling: Terrace level for floor/roof finishes.

• Junction treatment: Proper connection with walls, floors.

• Drainage provisions: Roof slope and drainage must be planned.

• Fixing provisions: For services like ceiling, utilities.

Rounding Off per IS 2-1960 (Summary)

This ensures consistent precision in test results and calculations as per IS 2118.

IS 2118: Materials Key Points

• Water: Must conform to IS 456-1978 (Clause 3.12). Suitable for mortar and concrete mixing.

• Steel Sections: Rolled steel sections per IS 808-1964; steel quality per IS 226-1975 (Clause 3.10.1).

• Reinforcement Steel: Mild and medium tensile steel bars as per IS specifications (Part I).

• Pozzolanic Materials: Burnt clay pozzolana, fly ash (Part I & II) as per respective IS standards.

• Sand & Aggregates: Sand for masonry mortar and plaster per IS specifications; broken brick aggregates and tiles must follow relevant IS codes.

• Storage & Handling (Clause 7.1): Materials (cement, lime, sand, aggregates, tiles, joists) must be stored to avoid deterioration per IS 4082-1977.

Summary Table of Relevant IS Codes for Materials in IS 2118

This ensures materials meet quality and durability requirements for lime concrete structures under IS 2118.

IS 2118 - Necessary Information for Design and Construction

Key Points from Clause 4.1 & 4.2:

For efficient design and construction of lime concrete terraces, provide detailed info on:

• Surface area & loading conditions: Dead load, live load, and any special loads.
• Supporting elements: Type (beams, slabs), spacing, and any restrictions.
• Leveling: Terrace level to receive finishes (floor/roof).
• Junction treatment: Details of connections with walls, adjacent floors.
• Drainage provisions: Roof slope, outlets for water drainage.
• Fixing provisions: Embedments or supports for services, ceiling, etc.

All this info must be communicated clearly to designers and contractors with proper drawings and instructions (Clause 4.2).

Additional Notes:

• Hand Beater (Clause 3.13 & Appendix C): Use a hand beater conforming to IS 2118 Appendix C for compacting lime broken brick aggregate concrete.
• Crude Oil Specification (Appendix A): For jack-arch construction, crude oil used must meet specifications in Appendix A.

Typical Loading Considerations for Lime Concrete Terrace:

Roof Slope for Drainage:

• Minimum slope: 1:100 (1% gradient) recommended for effective drainage.

flowchart TD
    A[Design Requirements] --> B[Surface Area & Loading]
    A --> C[Supporting Elements]
    A --> D[Level for Finish]
    A --> E[Junction Treatment]
    A --> F[Drainage Provisions]
    A --> G[Fixing Provisions]
    B --> H[Load Calculations]
    F --> I[Roof Slope & Outlets]

Summary: Provide comprehensive data on loads, support, levels, junctions, drainage, and fixing to ensure proper terrace design and construction per IS 2118.

IS 2118: Design & Structural Requirements for Precast Concrete

1. Design Standards Referenced:

   • Precast reinforced and prestressed concrete sections must comply with:
     • IS 456: 1978 (Plain and Reinforced Concrete)
     • IS 1343: 1960 (Prestressed Concrete)

2. Key Design Considerations (Clause 4.1):

   • Surface area & loading conditions
   • Supporting element types & arrangement restrictions
   • Terrace level for finishes
   • Junction treatment with adjacent elements
   • Roof slope & drainage provisions
   • Fixing provisions for services and ceilings

3. Material & Construction:

   • Must conform to IS 456 and IS 1343 for quality and durability.

Important Formulas (from IS 456 & IS 1343 references)

• Flexural Strength (IS 456):
  [ M_u \leq 0.87 f_y A_{st} (d - \frac{a}{2}) ] where (M_u) = ultimate moment, (f_y) = yield strength of steel, (A_{st}) = area of tension steel, (d) = effective depth, (a) = depth of equivalent stress block.

• Prestressing Force (IS 1343):
  [ P = \frac{M}{e} ] where (P) = prestressing force, (M) = moment, (e) = eccentricity.

Summary Table: Design Reference Standards

flowchart LR
    A[Design Requirements] --> B[Load & Surface Area]
    A --> C[Support Elements]
    A --> D[Terrace Level & Finish]
    A --> E[Junction Treatment]
    A --> F[Drainage & Slope]

IS 2118: Construction Facilities and Time Schedule

Key Points from Clauses 6.0 to 6.2.2:

• 6.0 Preparatory Work:
  Provide all necessary facilities for jack-arch terrace construction to ensure smooth execution.

• 6.2 Time Schedule:

  • 6.2.1: Time schedule must consider:
    • Completion of laying services (plumbing, electrical, etc.)
    • Strength development of supporting elements (curing time, concrete strength gain)
  • 6.2.2: Arrange schedule to avoid interference between construction activities. Avoid work during rainy season to prevent quality issues.

Practical Specifications:

Typical Time Schedule Considerations:

gantt
    title Construction Time Schedule
    dateFormat  YYYY-MM-DD
    section Services
    Laying Services          :done,    des1, 2024-01-01, 10d
    section Structural Work
    Concrete Pouring         :active,  des2, after des1, 7d
    Curing & Strength Gain   :         des3, after des2, 21d
    section Finishing
    Finishing Works          :         des4, after des3, 15d

Summary:
Plan the schedule ensuring services are laid before structural work, allow adequate curing time (minimum 7-28 days), avoid rainy season, and prevent activity clashes for quality and safety.

IS 2118: Preparation and Handling of Materials - Key Points

Storage, Transport, and Handling (Clause 7.1)

• Materials like cement, lime, sand, broken brick aggregate, tiles, and joists must be stored to prevent:
  • Deterioration
  • Loss
  • Impairment of structural properties
• Follow relevant IS standards (e.g., IS 4082-1977 for storage of cement).

Water Quality (Clause 1.3)

• Water used must comply with IS 456:3.12 (typically potable water free from harmful impurities).

Preparation (Clause 3.13)

• Use a hand beater conforming to Appendix C for compacting lime broken brick aggregate concrete.

Appendix B: Preparation of Lime-Concrete (Clause 7.2)

• Specifies materials and mix proportions for jack-arch construction lime concrete.
• Lime concrete mix typically includes:
  • Lime
  • Broken brick aggregate
  • Water (as per IS 456)
• Proper mixing and compaction are essential for strength.

Typical Storage Guidelines (from IS 4082-1977):

Hand Beater (Appendix C) - Key Specs:

• Weight: 2.5 to 3.5 kg
• Handle length: 500 mm approx.
• Used for manual compaction in small batches.

flowchart LR
    A[Material Delivery] --> B[Storage as per IS 4082]
    B --> C[Preparation of Lime Concrete]
    C --> D[Mixing (Lime + Aggregate + Water)]
    D --> E[Compaction using Hand Beater]
    E --> F[Use in Jack-Arch Construction]

Summary: Proper storage, water quality, material preparation, and compaction per IS 2118 ensure durable lime concrete for jack-arch structures.

Key Specifications & Formulas for Supporting Joists and Tie Rods (IS 2118):

Tie Rod Placement & Spacing (Clause 5.2.4.2)

• Tie rods are placed 75 mm above the bottom of the joist.
• Maximum spacing ≤ 20 × flange width of the joist.
• Anchoring: Use stout mild steel washers or angle irons.
• For insufficient wall thickness, use a separate encased beam for anchorage.

Tie Rod Function (Clause 2.7)

• Tie rods are mild steel tension rods connecting consecutive joists.
• Purpose: To pull joists together and relieve jack-arch thrust.

Tie Rod Provision in Spans (Clause 5.2.4.3)

• Provide tie rods in end spans of jack-arch series.
• Interior spans usually supported by adjacent arches; provide tie rods if local loads demand.
• For shorter end spans, provide tie rods in at least two spans near the end for lateral support.

Material Standards

• Tie rods: Steel conforming to IS 432 (Part I) - 1966.
• Steel quality: As per IS 226 - 1975.

Summary Table: Tie Rod Spacing

flowchart LR
    Joist -->|Tie Rod at 75mm above bottom| TieRod
    TieRod -->|Anchored by washers/angle irons| Anchorage
    Anchorage --> EndWall[End Wall or Encased Beam]
    JackArch -->|Thrust relieved by| TieRod

This ensures structural stability by controlling lateral thrust and maintaining joist alignment.

Key Specifications & Formulas for Brick Arch Construction (IS 2118):

1. Brick Size (Clause 3.1)

• Standard brick size suitable for jack-arch:
  190 mm × 90 mm × 40 mm

2. Mortar Mix & Laying (Clause 9.2)

• Bricks laid on edge in cement mortar:
  Cement : Sand = 1 : 4 (by volume) or equivalent lime mortar.
• Joint thickness at bottom ≤ 10 mm.
• Curing: Keep moist for ≥ 10 days before applying concrete.

3. Concrete Layer Over Arch (Clause 10.1)

• After brick arch hardens, apply:
  • Lime-broken brick aggregate concrete:
    Mix = 1 : 2 (slaked lime : broken brick aggregate by volume)
    OR
  • Lime-pozzolanic-fine aggregate mix:
    Mix = 1 : 1 : 1 (lime : pozzolanic material : fine aggregate by volume)
  • Initial thickness over crown: 75 mm

Summary Table

flowchart LR
    A[Brick Arch Construction] --> B[Brick Laying]
    B --> C[Bricks on edge, 1:4 Cement Mortar]
    C --> D[Curing ≥ 10 days]
    D --> E[Concrete Layer]
    E --> F[1:2 Lime:Brick Aggregate OR 1:1:1 Lime:Pozzolanic:Fine Aggregate]
    F --> G[Thickness 75 mm over crown]

This ensures durable jack-arch construction per IS 2118.

IS 2118: Lime Concrete for Jack-Arch Construction

Key Specifications (Clause 3.7 & Appendix B)

• Lime concrete is used for jack-arch floors/roofs.
• Prepared as per Appendix B of IS 2118 or IS 2541-1974.
• Mortars per IS 2250-1980.

Materials (Appendix B)

• Lime: Hydrated lime conforming to IS standards.
• Aggregate: Broken brick aggregate or suitable alternatives.
• Water: Clean and potable.

Typical Lime Concrete Mix (from Appendix B)

Preparation Method

1. Mix dry ingredients (lime + aggregate) thoroughly.
2. Add water gradually to achieve a plastic, workable consistency.
3. Lay immediately over jack-arch surfaces.
4. Compact well to avoid voids.

Reference Standards

• IS 2541-1974: Alternate lime concrete mix and preparation.
• IS 2250-1980: Mortar preparation guidelines.

flowchart TD
    A[Materials: Lime + Broken Brick Aggregate] --> B[Dry Mixing]
    B --> C[Add Water Gradually]
    C --> D[Mix to Plastic Consistency]
    D --> E[Lay on Jack-Arch Surface]
    E --> F[Compact Thoroughly]

This ensures durable, crack-resistant lime concrete suitable for jack-arch floors/roofs.

IS 2118: Key Points on Curing, Finishing, and Maintenance

1. Curing

• Clause 10.4:

  • Concrete must be cured by sprinkling water.
  • Minimum curing period: 6 days before laying floor/roof finish.

• Clause 11.4:

  • Finished terrace and ceiling surfaces require curing by water for at least 3 weeks.

2. Finishing

• Finishing details for roofs/floors with tiles are specified (refer to relevant sections in IS 2118).
• Use of waterproofing additives and their application methods are specified to enhance durability.

3. Maintenance

• Continuous curing by sprinkling or wet covering is essential during the curing period to prevent moisture loss.
• Proper compaction using a Hand Beater (Clause 3.13 & Appendix C) ensures uniform finishing and strength.

Summary Table

flowchart TD
    A[Concrete Placement] --> B[Curing by Water Sprinkling]
    B -->|6 days| C[Floor/Roof Finish]
    C --> D[Finished Surface Curing]
    D -->|3 weeks| E[Maintenance & Protection]

Note: Refer to Appendix C for hand beater specifications and IS 2118 sections on waterproofing additives for detailed procedures.

IS 2118: Treatment of Junctions – Key Points

The code emphasizes proper structural and load transfer detailing at junctions for jack-arch floors and roofs:

1. Junction Treatment Requirements (Clause 4.1d)

• Junctions between jack-arch floors and adjacent walls/floors must ensure:
  • Proper load transfer without overstressing masonry or steel.
  • Continuity and stability at intersections.
  • Accommodation for differential movement (thermal, shrinkage).

2. Support and Bearing (Clause 8.3)

• Joists fixed over masonry must rest on:

  • Cement concrete or stone bed blocks, or
  • Steel bearing plates designed to spread load safely.

  Purpose: Prevent local crushing of masonry.

3. Load Spreading Design

• Bearing plate or bed block size is based on:

[ \text{Area} = \frac{\text{Load on joist end}}{\text{Safe bearing pressure of masonry}} ]

• Typical safe bearing pressure for brick masonry: 1.5 to 2.5 N/mm² (confirm per project).

Summary Table: Bearing Plate/Bed Block Design

Additional Notes:

• Painting of steel/iron at junctions per IS 1477 (Parts I & II) ensures corrosion protection.
• Detailed junction design must consider drainage, fixing of services, and finishes (Clause 4.1).

flowchart LR
    Joist -->|Load Transfer| Bearing Plate/Bed Block
    Bearing Plate/Bed Block -->|Spreads Load| Masonry
    Masonry -->|Supports| Wall/Column
    Wall/Column -->|Transfers Load| Foundation

In essence: Ensure junctions have adequate bearing area and protection to maintain integrity and durability.

IS 2118: Properties & Testing of Crude Oil for Jack-Arch Construction

Key Specifications (Appendix A):

• Specific Gravity (A-2): Crude oil must conform to specified limits (typically around 0.85 to 0.95, depending on grade).

• Viscosity Number (A-6.1):

  • Tested as per procedure in A-6.1.1
  • Viscosity Number Range: 40 to 45 (ensures proper waterproofing properties)

Testing Procedures:

• Viscosity Test (Clause A-6.1.1):
  • Conducted using standard viscometers at specified temperatures (usually 40°C).
  • Ensures oil flows adequately for impregnation without being too fluid.

Summary Table:

Notes:

• Crude oil must be petroleum-based and suitable for waterproofing lime concrete.
• Conformance to these ensures durability and moisture resistance in jack-arch construction.

flowchart TD
    A[Crude Oil] --> B[Specific Gravity Test]
    A --> C[Viscosity Number Test]
    B --> D{Within Limits?}
    C --> E{40 ≤ Viscosity ≤ 45?}
    D -->|Yes| F[Approved for Use]
    D -->|No| G[Reject]
    E -->|Yes| F
    E -->|No| G

This ensures only suitable crude oil is used for waterproofing in jack-arch construction per IS 2118.

IS 2118 — Preparation of Lime Concrete Mixes (Appendix B)

Key Specifications for Lime Concrete in Jack-Arch Construction:

• Materials:

  • Lime: Hydrated lime conforming to IS 712.
  • Aggregate: Broken brick aggregate or coarse sand.
  • Water: Clean, potable water.

• Mix Proportions:

  • Typical lime concrete mix ratio:
    1 part lime : 3 parts broken brick aggregate (by volume)
  • Alternate mix (existing practice):
    Lime : Sand : Broken brick aggregate = 1 : 1 : 3

• Preparation Method:

  1. Mix dry lime and aggregate thoroughly before adding water.
  2. Add water gradually to achieve a workable consistency.
  3. Mix until uniform, avoiding excess water to prevent segregation.
  4. Use immediately after mixing for laying over jack-arches.

• Reference Standards:

  • Mortar preparation as per IS 2250-1980.
  • Lime concrete preparation per IS 2541-1974.

Summary Table: Lime Concrete Mix Ratios

flowchart TD
    A[Start] --> B[Measure Lime and Aggregate]
    B --> C[Dry Mix Lime & Aggregate]
    C --> D[Add Water Gradually]
    D --> E[Mix to Uniform Consistency]
    E --> F[Use Immediately for Jack-Arch]

Note: Proper curing is essential for strength development in lime concrete.

IS 2118 - Specification for Hand Beater (Appendix C)

• Dimensions:

  • Length of beater (excluding handle): 300 mm
  • Handle length: 150 mm
  • Handle diameter: 40 mm
  • Depth of hand beater: 100 mm

• Shape & Material:

  • Cross-section: Triangular (refer Fig. 4)
  • Material: Hard durable timber
  • Beating edge: Rounded off for effective compaction and durability

• Use:

  • Specifically for compacting lime broken brick aggregate concrete in jack-arch construction.

Summary Table

flowchart LR
    A[Handle (150 mm, Ø40 mm)] --> B[Triangular Beater (300 mm length)]
    B --> C[Depth 100 mm]
    B --> D[Rounded Beating Edge]
    style B fill:#f9f,stroke:#333,stroke-width:2px

This ensures proper compaction and longevity of the hand beater as per IS 2118.