Code of Practice for Construction of Floor and Roof with Joists and Filler Blocks, Part 3: With Precast Hollow Clay Block Joists and Hollow Clay Filler Blocks

IS 6061 Part 3 (1981) - Scope Summary & Key References

Scope:
IS 6061 Part 3 covers the construction practices for floors and roofs using joists and filler blocks, focusing on structural clay block slabs and related waterproofing.

Key Specifications & References for Waterproofing (Clause 7.3)

Roof waterproofing can be done according to any of the following IS codes:

Design Coefficients for Structural Clay Block Slabs (Clause 5.6.1)

Bending Moment Coefficients

Shear Force Coefficients

Note: Multiply coefficients by total design load and effective span to get moments and shear forces.

Summary Diagram: Waterproofing Options

graph LR
A[Roof Waterproofing] --> B[Bitumen Felts (IS 1346)]
A --> C[Lime Concrete (IS 3036)]
A --> D[Bitumen Mastic (IS 4365)]
A --> E[Polyethylene Film (IS 7290)]

**Use these references and coefficients for design and detailing

General Design Requirements for Structural Clay Block Slab (IS 6061 Part 3)

Key Points from Clauses:

• Clause 5.1: Design based on structural analysis per Clauses 5.2 to 5.9.
• Clause 5.3: Design for two loading stages (construction and service).
• Clause 5.9.2: Shear stress must be within permissible limits.

Important Tables for Design (Clause 5.6.1):

1. Bending Moment Coefficients (Multiply by total design load × effective span)

2. Shear Force Coefficients (Multiply by total design load)

Design Formulae:

• Bending Moment, M = Coefficient × Design Load × Effective Span
• Shear Force, V = Coefficient × Design Load

Notes:

• Design must consider two stages of loading: during construction and in service.
• Ensure shear stress ≤ permissible shear stress for clay blocks.
• Use effective span as per support conditions.

flowchart TD
    A[Start: Structural Clay Block Slab Design]
    B[Determine Loads: Dead + Imposed]
    C[Select Coefficients from Tables]
    D[Calculate Bending Moments and Shear Forces]
    E[

IS 6061 (Part 3) - 1981: Materials Key Points

• Waterproofing Standards (Clause 7.3):
  Roof waterproofing must comply with one of these IS codes:

  • IS 1346-1976: Bitumen felts waterproofing
  • IS 3036-1980: Epoxy resin floor toppings
  • IS 4365-1967: Flexible PVC sheet and tile flooring
  • IS 7290-1973: Burnt clay brick flooring

• Material Specifications:
  Refer to relevant IS codes for material properties and application methods. For example:

  • Bitumen felts (IS 1346) specify types, thickness, and application
  • Epoxy resin floors (IS 3036) detail mix ratios and curing
  • PVC sheets (IS 4365) define flexibility and thickness requirements

• Design Coefficients for Structural Clay Block Slabs (Clause 5.6.1):

• Usage: Multiply coefficients by total design load and effective span to find moments and shear forces.

Summary Diagram: Material Specification Flow

graph TD
  A[Roof Waterproofing] --> B[Bitumen Felts (IS 1346)]
  A --> C[Epoxy Resin Floor (IS 3036)]
  A --> D[PVC Sheet Flooring (IS 4365)]
  A --> E[Clay Brick Flooring (IS 7290)]
  F[Structural Clay Block Slab Design] --> G[Bending Moment Coefficients]
  F --> H[Shear Force Coefficients]

For detailed material properties and application methods, always refer to the respective

Fabrication and Curing of Precast Joists (IS 6061 Part 3)

Fabrication (Clause 4.2)

• Use hollow clay blocks, wetted and skin-dry.
• Place blocks end-to-end with wider base on platform.
• Joint blocks with 1:3 cement:sand mortar or equivalent cement-lime mortar.
• Place two cleaned, oiled wooden planks on sides, held by mild steel clamps.
• Insert designed reinforcement in hollow spaces with proper cover.
• Fill hollow spaces with minimum M15 grade concrete.
• Remove side planks after 45–90 minutes depending on weather.

Curing (Clause 4.3)

• Start curing with water 1 day after casting at the precasting platform.
• After ~4 days (when concrete gains handling strength), invert joists and transfer to curing yard.
• Maintain continuous moisture for at least 14 days from casting.

Additional Specifications

• Reinforcement bars as per IS specifications for mild steel, medium tensile, or high strength deformed bars.
• Fill spaces between joists with M15 concrete (Clause 6.2).
• Provide negative reinforcement for partial fixity or cantilever joists.

Summary Table

flowchart TD
    A[Place wetted clay blocks] --> B[Joint with mortar]
    B --> C[Place side wooden planks & clamps]
    C --> D[Insert reinforcement]
    D --> E[Fill hollow spaces with M15 concrete]
    E --> F[Remove side planks after 45-90 min]
    F --> G[Cure with water at platform (Day 1)]
    G --> H[Invert joists

Design Loads and Loading Arrangements (IS 6061 Part 3)

1. Design Loads (Clause 5.2)

• Live load as per IS 875-1964.
• Two-stage loading for prefabricated clay block slabs:
  • Stage 1: Self-weight and construction loads.
  • Stage 2: Superimposed dead load + live load.

2. Loading Arrangements (Clause 5.6)

For continuous slabs over multiple spans, consider these load cases:

3. Bending Moment Coefficients (Table 1, Clause 5.6.1)

Note: Multiply coefficients by total design load × effective span to get moments.

4. Shear Force Coefficients (Table 2, Clause 5.6.1)

Note: Multiply coefficients by total design load to get shear forces.

Summary Formula for Moments:

[ M = C_m \times w \times L ]

• (M) = Bending moment
• (C_m) = Moment coefficient (from

IS 6061 Part 3: Construction & Assembly of Joists and Filler Blocks

Key Specifications:

• Joist and Filler Block Assembly: Joists are spaced and filler blocks (usually clay blocks) are placed between them to form floors/roofs.
• Joint Breaking (Clause 6.1.1): Use half-length filler blocks at joints between joists and blocks to ensure staggered joints, enhancing structural integrity and load distribution.

Typical Assembly Guidelines:

• Joist Spacing: As per design load and span (commonly 450mm to 600mm center-to-center).
• Filler Blocks: Laid tightly between joists, with mortar bedding.
• Reinforcement: Mild steel rods or mesh may be provided over filler blocks before plastering.

Important Notes:

• Ensure proper bearing length of joists on walls (usually minimum 100 mm).
• Maintain uniform thickness of filler blocks for level flooring.
• Provide adequate curing for mortar and blocks to achieve strength.

Simplified Diagram (Fig. 3 Concept):

graph LR
    A[Wall] --> B[Joist]
    B --> C[Filler Block (Half units at joints)]
    C --> D[Joist]
    D --> E[Wall]
    style B fill:#f9f,stroke:#333,stroke-width:2px
    style C fill:#bbf,stroke:#333,stroke-width:1px

This practice ensures a durable, crack-resistant floor/roof system with good load transfer.

IS 6061 Part 3 (1981) - Finishing of Floors and Roofs: Key Points

Relevant IS Codes for Floor & Roof Finishes (Clause 7.1.1)

Waterproofing of Roofs (Clause 7.3)

• IS 1346-1976: Waterproofing with bitumen felts
• IS 3036-1980: Lime concrete waterproofing
• IS 4365-1967: Bitumen mastic application for waterproofing
• IS 7290-1973: Use of polyethylene film for waterproofing

Summary Table for Finishing Selection

Reinforcement Detailing per IS 6061 Part 3

Key Specifications:

• Reinforcement Standards: Use bars conforming to IS 432 (Part 1)-1966, IS 1139-1966, or IS 1786-1979.
• Minimum Cover: 15 mm minimum clear cover to reinforcement (Clause 6.5.3).
• Splicing: Avoid splicing of reinforcement bars wherever possible.

Design Parameters:

Table 1: Bending Moment Coefficients (Clause 5.6.1)

Table 2: Shear Force Coefficients (Clause 5.6.1)

Summary:

• Calculate moments and shear by multiplying coefficients with design loads.
• Ensure minimum 15 mm cover and avoid splicing.
• Follow IS 456 for slab depth design.

flowchart TD
    A[Design Load] --> B[Calculate Moments]
    A --> C

IS 6061 Part 3 (1981) lacks explicit clauses on Handling, Storage, and Transportation. However, based on standard engineering practice and related IS codes:

Handling

• Use slings, chains, or clamps designed to avoid damage.
• Distribute load evenly to prevent bending or distortion.
• Avoid dropping or impact loading.

Storage

• Store on flat, level surfaces with supports at regular intervals (typically every 1.5 to 2 m for beams).
• Protect from moisture and corrosive environments.
• Stack with spacers to allow air circulation.

Transportation

• Secure loads firmly to avoid shifting.
• Use padding to prevent surface damage.
• Follow weight limits and vehicle capacity.

Typical Support Spacing for Storage (Beams/Sections)

flowchart LR
    A[Handling] --> B[Use proper slings/clamps]
    A --> C[Distribute load evenly]
    D[Storage] --> E[Flat, level surface]
    D --> F[Supports every 1.5-2.5 m]
    D --> G[Protect from moisture]
    H[Transportation] --> I[Secure loads]
    H --> J[Use padding]
    H --> K[Follow vehicle limits]

For detailed specs, consult IS 800 and IS 875 for handling and transportation guidelines.

Support and Bearing Requirements per IS 6061 Part 3

1. Bearing Specifications (Clause 6.3)

• Minimum bearing length along span: 75 mm
• Minimum bearing length at slab ends: 20 mm

2. Bending Moment Coefficients (Clause 5.6.1, Table 1)

• Moment (M) = Coefficient × Total design load (W) × Effective span (l)

3. Shear Force Coefficients (Clause 5.6.1, Table 2)

• Shear Force (V) = Coefficient × Total design load (W)

4. Simply Supported Slab Moments (Clause 5.7)

• Positive moment at midspan:
  [ M = \frac{W l^2}{8} ]
• Negative moment at support (partial restraint):
  [ M = \frac{W l^2}{24} ]

Summary

• Use moment and shear coefficients from Tables 1 & 2 for continuous slabs with uniform load.
• Ensure minimum bearing lengths of 75 mm (span direction) and 20 mm (ends).
• Design simply supported slabs

Moment and Shear Force Calculations
IS 6061 Part 3 - Key Formulas & Tables

1. Bending Moment Coefficients (Clause 5.6.1, Table 1)

Moment (M) = Coefficient × Total design load × Effective span

2. Shear Force Coefficients (Clause 5.6.1, Table 2)

Shear Force (V) = Coefficient × Total design load

3. Shear Stress Calculation (Clause 5.9)

[ q = \frac{V}{b \times d} ]

• V = Shear force at the section
• b = Minimum width of web
• d = Effective depth

4. Notes

• For unequal spans or unequal loading at supports, use the larger negative moment for design (Clause 5.6.1.1).
• Applicable for slabs with 3 or more spans with span lengths within 15% of the longest span.

flowchart TD
    A[Total Design Load] --> B[Calculate Moments]
    B --> C{Use Table 1 Coefficients}
    C --> D[Moment at End Span]
    C --> E[Moment at Interior Span]

IS 6061 Part 3 - Quality Control & Safety: Key Points

1. Quality Control References:

• Waterproofing must comply with related IS codes:
  • IS 1346-1976 (Bitumen felts waterproofing)
  • IS 3036-1980 (In-situ cement concrete flooring)
  • IS 4365-1967 (Flexible PVC flooring)
  • IS 7290-1973 (Burnt clay brick flooring)

2. Design Coefficients for Structural Clay Block Slabs (Clause 5.6.1):

3. Safety & Compliance:

• Final test values must be rounded per IS 2-1960.
• Maintain significant figures as per specified values.
• Follow referenced IS codes for specific construction practices ensuring safety and durability.

flowchart TD
    A[Start: Design & Construction] --> B[Select Waterproofing per IS codes]
    B --> C[Apply Bending Moment Coefficients]
    C --> D[Apply Shear Force Coefficients]
    D --> E[Perform Quality Control Tests]
    E --> F[Round off values as per IS 2-1960]
    F --> G[Ensure Safety & Compliance]
    G --> H[Construction Approval]

Summary: Use the bending moment and shear force coefficients for design loads, adhere to referenced IS standards

IS 6061 (Part 3) - 1981: References to Related Indian Standards

This part of IS 6061 references key Indian Standards for waterproofing and roofing practices:

Key Related IS Codes for Waterproofing Roofs (Clause 7.3)

Other Related IS Codes on Floor and Roof Construction

• IS 2118-1980: Jack-arch built-up floor/roof construction
• IS 2119-1980: Brick-cum-concrete composite floor/roof
• IS 2792-1964: Stone slab over joist floor design
• IS 2858-1964: Roofing with Mangalore tiles
• IS 6061 (Parts I, II, IV): Construction with joists and filler blocks (concrete, clay, precast)
• IS 6332-1971: Precast doubly-curved shell units for floors/roofs

SI Units Relevant to Structural Engineering (Summary)

Summary Diagram of IS 6061 Part 3 References

graph TD
    A[IS 6061 (Part 3) - Waterproofing & Roof] --> B[IS 1346 - Bitumen Felts]
    A --> C[IS 3036 - Lime Concrete]
    A --> D[IS 4365 - Bitumen Mastic]
    A -->