Code of Practice for Construction of Floor and Roof with Joists and Filler Blocks, Part IV: With Precast Hollow Clay Block Slab Panels

Scope of IS 6061 Part 4 (Clause 5.6.1):

This part covers design coefficients for continuous slabs spanning three or more spans with uniform loads, where spans differ by no more than 15% from the longest.

Key Formulas & Tables for Bending Moments and Shear Forces:

1. Bending Moment Coefficients (Table 1):

• Moment = Coefficient × Total design load × Effective span

2. Shear Force Coefficients (Table 2):

• Shear Force = Coefficient × Total design load

Notes:

• These coefficients are approximate and used unless more precise analysis is available.
• Reinforcement should conform to IS 432 (Part I), IS 1139, or IS 1786.

flowchart TD
    A[Continuous Slabs] --> B{Uniform Load}
    B --> C{Span Difference ≤ 15%}
    C --> D[Use Coefficients from Tables]
    D --> E[Bending Moment Coefficients]
    D --> F[Shear Force Coefficients]
    E --> G[Calculate Moment = Coeff × Load × Span]
    F --> H[Calculate Shear = Coeff × Load]

This summary helps in quick design checks for

IS 6061 Part 4: Key Materials Specifications & Design Coefficients

1. Reinforcement Materials (Clause 2.4)

• Reinforcement shall conform to:
  • IS 432 (Part I) - 1966
  • IS 1139 - 1966
  • IS 1786 - 1979

2. Bending Moment Coefficients (Clause 5.6.1)

Moment = Coefficient × Total Design Load × Effective Span

3. Shear Force Coefficients (Clause 5.6.1)

Shear Force = Coefficient × Total Design Load

4. Finishing Materials (Clause 7.1.1)

IS 6061 Part 4: Preparatory Work - Key Points

Clause 3.1: Preparatory Work

• Supporting elements (walls, pillars, beams, frames) must be:
  • Completed and well cured before flooring/roofing.
  • Top surfaces should be level finished.
• Provide plain cement concrete or mortar bed on load-bearing walls if needed.
• Arrange for service pipes, conduits, fixtures passing through floors/roofs during preparation.

Reinforcement Standards (Clause 2.4)

• Reinforcement must conform to:
  • IS 432 (Part I) - 1966
  • IS 1139 - 1966
  • IS 1786 - 1979 (high strength deformed bars)

Useful Tables for Design (Clause 5.6.1)

Multiply coefficients by total design load and effective span for moments and loads for shear.

Finishing Standards (Clause 7.1.1)

Common floor/roof finishes per IS codes:

Summary Diagram: Preparatory Work Flow

flowchart TD
    A[Complete Supporting Elements] --> B[Cure Properly]
    B --> C[Level Finish Top Surface]
    C --> D[Provide Mortar Bed if Needed]
    D --> E[Arrange Service Pipes & Fixtures]
    E --> F[Start Flooring/Roofing Work]

**Ensure all preparatory steps are followed for durable, defect-free floor/roof construction

IS 6061 Part 4: Casting, Curing, and Maturing of Slab Panels

Key Specifications:

• Casting:

  • Slab panels cast with hollow structural clay blocks on a level platform.
  • Platform protected from direct sun and strong wind to avoid quick drying (Clause 4.1).
  • Panels placed side by side, abutting each other over a finished level support (Clause 6.1).
  • Joints finished with 1:2 cement:sand mortar, rule pointed; gaps filled with mortar from the top.

• Curing:

  • After casting, water curing for minimum 14 days (Clause 4.3).
  • Followed by air curing for another 14 days.

• Supporting Elements:

  • Walls, pillars, beams, etc., must be completed and well cured before flooring or roofing.
  • Top surfaces must be level finished.
  • Provision for fixing pipes, conduits, fixtures must be planned (Clause 3.1).

Summary Table for Curing Periods

Important Notes:

• Proper curing ensures strength development and durability.
• Mortar ratio for joints: 1:2 (cement:sand).
• Ensure level and stable support before casting.

flowchart TD
    A[Prepare Level Platform] --> B[Place Hollow Clay Blocks]
    B --> C[Cast Slab Panel]
    C --> D[Water Cure for 14 Days]
    D --> E[Air Cure for 14 Days]
    E --> F[Ready for Use]

This ensures slab panels achieve proper strength and durability as per IS 6061 Part 4.

IS 6061 Part 4: General Design Requirements (Clause 5.1 to 5.6.1)

Key Specifications:

• Design Load: Live load as per IS 875-1964 (Clause 5.2).
• Slab Panel Handling: Avoid direct ground contact; stack vertically/horizontally with props aligned (Clause 4.5).
• Design Basis: Structural analysis per Clauses 5.2 to 5.8 (Clause 5.1).

Bending Moment Coefficients (Clause 5.6.1, Table 1)

Moment = Coefficient × Total Design Load × Effective Span

Shear Force Coefficients (Clause 5.6.1, Table 2)

Shear Force = Coefficient × Total Design Load

Summary Diagram:

flowchart LR
    A[Design Load per IS 875] --> B[Calculate Moments]
    A --> C[Calculate Shear Forces]
    B --> D{Use Coefficients from Table 1}
    C --> E{Use Coefficients from Table 2}
    D --> F[Moment = Coeff × Load × Span]
    E --> G[Shear = Coeff × Load]

Note:

Assembly of Floor or Roof (IS 6061 Part 4)

Key Specifications:

• Supporting elements (walls, pillars, beams) must be completed and well-cured before flooring/roofing.
• Surfaces must be level finished; mortar or PCC bed may be provided over load-bearing walls.
• Allow for service pipes, conduits, fixtures in the floor/roof.

Shear Stress:

• Shear stress in structural clay block slabs must be within permissible limits (Clause 5.8.2).

Bending Moment Coefficients (Clause 5.6.1, Table 1)

Moment = Coefficient × Total Design Load × Effective Span

Shear Force Coefficients (Clause 5.6.1, Table 2)

Shear Force = Coefficient × Total Design Load

Summary Diagram of Load Distribution:

graph LR
A[End Span] -->|Moment Coeff +1/12| B[Middle End Span]
B -->|Moment Coeff +1/24| C[Middle Interior Span]
C -->|Moment Coeff -1/10| D[First Interior Support]
D -->|Moment Coeff -1/12| E[Other Interior Supports]

References:

• Ensure curing and finishing as

IS 6061 Part 4 - Finishing: Key Points

1. Relevant IS Standards for Floor/Roof Finishes (Clause 7.1.1)

2. General Specifications (Clause 3.1)

• Supporting elements (walls, beams) must be level finished and cured before finishing.
• Provide plain cement concrete or mortar bed over load-bearing walls if needed.
• Arrange for service pipes/conduits before finishing.

3. Structural Design Coefficients (Clause 5.6.1)

Bending Moment Coefficients

Shear Force Coefficients

*Note: