Construction of hollow and solid concrete block masonry - Code of practice

IS 2572: Scope - Key Points & References

Scope Summary:

• IS 2572 covers specifications, design, and construction of masonry walls and partitions.
• It includes materials, workmanship, and detailing for efficient planning and execution.

Key Specifications & Requirements

• Planning & Design Info (Clause 4.1):

  • Layout plans with walls, openings, stairs, columns.
  • Dimensions and sections showing reinforcement (bands, ties).
  • Architectural features and embedded fittings.
  • Fixing details for door/window frames.
  • Service line locations (water, drainage, electrical).
  • Grade of masonry blocks.

• Time Schedule (Clause 5.3):

  • Dates for drawings/specifications supply.
  • Material delivery schedule.
  • Start & completion of wall construction and finishing.

Referenced Indian Standards (Selected)

Important Notes

• All referenced IS codes are subject to revision; latest editions should be used.
• Materials like cement, aggregates, steel reinforcement conform to their respective IS standards.
• Flexible connections and anchors (e.g., metal anchor 32×6 mm) are detailed for intersecting walls (Fig. 12).

flowchart TD
    A[Planning & Design Info] --> B[Layout & Dimensions]
    A --> C[Architectural & Fittings Details]
    A --> D[Service Lines Location]
    A --> E[Block Grade]
    F[Time Schedule] --> G[Drawings & Specs Supply]
    F --> H[Material Delivery]
    F --> I[Construction Start & End]
    J[Referenced IS Codes] --> K[Cement & Aggregates]
    J --> L[Concrete & Masonry Units]
    J

IS 2572 References Summary

IS 2572 refers extensively to Indian Standards (IS) for materials, design, and construction practices related to masonry and concrete. Key referenced standards include:

Important Notes:

• These standards cover raw materials, stacking/storage, design loads, seismic design, and construction practices.
• Always use the latest editions for compliance.
• For masonry terminology and practices, refer to IS 2185 (Part 1) and IS 2212.

Typical Reference Use in IS 2572:

• Material specifications: Cement, aggregates, steel.
• Design codes: Loadings, earthquake resistance.
• Construction practices: Mortar, masonry units, curing.

graph LR
A[IS 2572] --> B[Material Specs]
A --> C[Design Codes]
A --> D[Construction Practices]

B --> IS269[IS 269: Cement]
B --> IS383[IS 383: Aggregates]
B --> IS432[IS 432: Steel Reinforcement]

C --> IS456[IS 456: Concrete Design]
C --> IS1893[IS 1893: Earthquake Design]

D --> IS2185[IS 2185: Masonry Units]
D --> IS2212[IS 2212: Brickwork]
D --> IS2250[IS 2250

IS 2572 - Terminology Key Points

IS 2572 references terminology mainly related to masonry and related materials. For detailed definitions, refer to:

• IS 2185 (Part 1): 1979 — Specification for concrete masonry units (hollow and solid blocks)
• IS 2212: 1991 — Code of practice for brickwork

Key Terminology Highlights:

• Metal Anchor: Typically a C.I. (Cast Iron) strip, e.g., 32×6 mm, used for flexible connections.
• Elastic Joint Sealant: Material used to fill joints allowing movement.
• Flexible Connections: Methods to join intersecting walls to accommodate differential movement.

Important IS References for Masonry Terminology and Specifications:

Notes:

• Terminology aligns with materials, construction methods, and maintenance.
• Always use the latest editions of referenced IS codes for updated definitions and practices.

graph LR
A[Masonry Terminology] --> B[IS 2185 (Part 1): Concrete Blocks]
A --> C[IS 2212: Brickwork Practice]
A --> D[Metal Anchors & Flexible Connections]
A --> E[Elastic Joint Sealants]

For precise definitions, consult the above IS codes directly.

IS 2572 - Clause 4: Necessary Information for Masonry Work

Key Specifications to be Furnished (Clause 4.1)

Provide detailed info to responsible personnel for proper planning and execution:

• Layout Plans: Walls, doors, windows, openings, stairs, columns.
• Dimensions: Full structure dimensions, sections, reinforced bands, ties.
• Architectural Details: Mouldings, special works, embedded fittings.
• Fixing Details: Door/window frame attachments to masonry.
• Service Lines: Locations/details of water, drainage, sewerage, electrical, telecom.
• Block Grade: Specify masonry block grade.

Communication (Clause 4.2)

• All above info must be shared with those executing masonry.
• Necessary drawings and instructions for work planning must be provided.

Related Indian Standards (Key References)

Summary Diagram of Information Flow

flowchart TD
    A[Design Team] --> B[Prepare Layout Plans]
    A --> C[Specify Dimensions & Sections]
    A --> D[Detail Architectural Features]
    A --> E[Specify Fixing Details]
    A --> F[Provide Service Lines Info]
    A --> G[Specify Block Grade]
    B & C & D & E & F & G --> H[Provide Drawings & Instructions]
    H --> I[Masonry Execution Team]

This ensures clarity, accuracy, and quality in masonry construction per IS 2572.

IS 2572: Planning and Scheduling of Masonry Work

Key Points from IS 2572:

• Coordination (Clause 5.1):
  Masonry work schedule must be coordinated with other trades to avoid interference.

• Time Schedule Contents (Clause 5.3):
  Include dates for:

  • Supply of drawings & material specs
  • Delivery of masonry units & accessories
  • Start & completion of masonry operations

• Information for Planning (Clause 4.1 & 4.2):
  Provide detailed:

  • Layout plans with walls, openings, columns, stairs
  • Dimensions & sections showing reinforcements (bands, ties)
  • Architectural details, mouldings, fittings
  • Fixing details for door/window frames
  • Service line locations (water, drainage, electrical, etc.)
  • Grade of blocks

Practical Scheduling Tips:

Summary Diagram:

gantt
    title Masonry Work Schedule
    dateFormat  YYYY-MM-DD
    section Planning
    Drawings & Specs Supply      :done, 2024-06-01, 7d
    Material Delivery            :active, 2024-06-08, 14d
    section Execution
    Masonry Work Start           :2024-06-22, 21d
    Curing & Finishing           :2024-07-13, 14d

Ensure all trades have updated info and drawings before starting masonry to optimize workflow and avoid rework.

IS 2572: Materials - Key Specifications & References

Cement, Lime, Aggregates

• Must comply with relevant IS codes:
  • Cement: IS 269 (OPC 33 grade), IS 455 (Portland slag cement), IS 1489 (Pozzolana cement), IS 8112 (OPC 43 grade), IS 12269 (OPC 53 grade)
  • Lime: IS 712 (Building limes), IS 1635 (Field slaking & putty prep)
  • Aggregates: IS 383 (Coarse & fine aggregates), IS 1542 (Sand for plaster), IS 2116 (Sand for masonry mortars)

Storage & Handling (Clause 8.2)

• Follow IS 4082 recommendations for stacking and storage to prevent contamination and deterioration.

Mortar Mix Sand Proportions (Clause 6.5)

• Use higher sand proportion if sand is well graded (between max and min particle sizes).
• Use lower sand proportion if sand is fine and poorly graded.

Referenced IS Codes Table (Partial)

Summary

• Use IS codes for material specs.
• Store materials per IS 4082.
• Adjust sand content in mortar based on grading.
• Refer to IS 456 for concrete practices.

flowchart LR
    Cement -->|IS 269, 455, 1489| Materials
    Lime -->|IS 712, 1635| Materials
    Aggregates -->|IS 383, 1542, 2116| Materials
    Materials --> Storage[Storage & Handling per IS 4082]
    Materials --> Mortar[Mortar Mix Sand Proportions]

IS 2572: Design Considerations - Key Points

1. Mortar Mix Sand Proportions (Clause 6.5)

• Use higher sand proportion if sand is well graded between max and min particle sizes.
• Use lower sand proportion if sand is fine and not graded.

2. Structural Design (Clause 7)

• Flexible connections for intersecting walls use metal anchors (C.I. 32×6 mm) and elastic joint sealants (Fig. 12).
• Metal anchors spaced vertically at 1.2 m with a 50 mm embedment.

3. Load Considerations

• Follow IS 875 (Parts 1 to 5) for:
  • Dead loads (unit weights)
  • Imposed loads
  • Wind loads
  • Snow loads
  • Special load combinations

4. Slenderness Reduction (Clause 2.5)

• Reduce permissible stresses for slender components to avoid buckling.

5. Component Isolation (Clause 1.2.2)

• Structural separations allowed if no damage from relative displacements occurs.

Important Related IS Codes for Design Reference

Summary Table: Sand Proportion for Mortar (Indicative)

flowchart TD
    A[Mortar Mix Design] --> B{Sand Grading}
    B -->|Well Graded| C[Use Higher Sand Content]
    B -->|Fine, Ungraded| D[Use Lower Sand Content]
    E[Wall Connections] --> F[Metal Anchor 32x6

IS 2572 - Storage and Handling of Materials: Key Points

1. Storage Requirements (Clause 8.1 & 8.2):

   • Blocks must be stored off the ground on planks/supports to avoid moisture.
   • Cover blocks to protect from wetting.
   • Handle blocks carefully; reject damaged units.
   • Cement, lime, aggregates, and masonry materials must be stored as per their relevant IS codes (see IS 4082 for stacking and storage guidelines).

2. Relevant IS Codes for Materials Storage & Handling:

   Material	IS Code(s)	Notes
   Ordinary Portland Cement	IS 269:1989, IS 8112:1980, IS 12269:1987	Specifications for grades of cement
   Aggregates	IS 383:1970	Coarse and fine aggregates specs
   Lime	IS 712:1984, IS 1635:1992	Building lime and putty preparation
   Masonry Blocks	IS 2185 (Part 1):1979	Concrete masonry units specs
   Cement Mortar	IS 4082:1996	Recommendations on stacking and storage
   Sand	IS 1542:1992, IS 2116:1980	Sand for plaster and masonry mortar

3. Handling & Stacking Guidelines (per IS 4082):

   • Stack materials on raised platforms to avoid ground contact.
   • Maintain dry, well-ventilated storage.
   • Avoid stacking beyond recommended heights to prevent crushing.
   • Segregate different materials to prevent contamination.

4. Unit Weights for Load Calculations (from IS 875 Part 1):

   • Cement: ~1440 kg/m³
   • Sand: ~1600 kg/m³
   • Aggregate: ~1500-1700 kg/m³
   • Masonry blocks: Varies by type (refer IS 2185)

Summary Diagram: Storage Setup for Masonry Blocks

graph TD
    Ground -->|Supports| Planks
    Planks -->|Stacked Blocks| MasonryBlocks
    MasonryBlocks -->|Cover| ProtectiveSheet
    Note[Keep dry & ventilated]

Workmanship in IS 2572: Key Specifications & Guidelines

1. Material Storage & Handling (Clause 8.2):

• Cement, lime, aggregates, and masonry materials must be stored and handled per relevant IS specifications (e.g., IS 4082 for stacking and storage).
• Proper storage prevents contamination and moisture ingress, ensuring material quality.

2. Preparatory Work (Clauses 4.1 & 4.2):

• Detailed information must be provided to workers, including:
  • Layout plans with walls, openings, columns, stairs.
  • Dimensions and sections showing reinforced bands, ties.
  • Architectural details and embedded fittings.
  • Fixing details for door/window frames.
  • Service line locations (water, drainage, electrical).
  • Block grade specifications.

3. Workmanship Quality Control:

• Follow IS codes for materials (e.g., IS 269 for OPC, IS 383 for aggregates).
• Use metal anchors and flexible connections as per Fig. 12 for intersecting walls to allow movement and avoid cracks.
• Maintain verticality and alignment (e.g., metal anchor 1.2 m DC vertically, 50 mm embedment).

Summary Table: Key IS Codes for Workmanship

flowchart TD
    A[Material Storage] --> B[Handling as per IS 4082]
    B --> C[Quality Control]
    C --> D[Work Execution]
    D --> E[Use of Metal Anchors & Flexible Connections]
    E --> F[Final Masonry Work]

In brief: Proper planning, material handling, and adherence to IS codes ensure durable masonry workmanship per IS

IS 2572: Foundation and Basement Masonry Key Points

Mortar Mix Proportions (Clause 6.9.2, Table 1)

Damp Proofing (Clause 10.1.2)

• Use richer mortar in damp soils to prevent capillary moisture rise.
• Provide a Damp Proof Course (DPC):
  • 25 mm thick layer of 1:2 cement mortar, OR
  • Approved bituminous course.

Construction Notes (Clause 10.1)

• Foundation and basement masonry must be laid carefully with specified mortar.
• Reinforcement requires richer mortar with less sand.

Summary:

• For foundations and damp conditions, use 1:1:6-7 (cement:lime:sand) or 1:4-5 (cement:sand) mortar.
• Always include a DPC layer to prevent moisture ingress.

flowchart TD
    A[Foundation Masonry] --> B[Mortar Mix]
    B --> C{Condition?}
    C -->|Normal| D[1:1:9-10 (C:L:S)]
    C -->|Severe Load/Damp Soil| E[1:1:6-7 (C:L:S)]
    C -->|Reinforced| F[1:4-5 (C:S)]
    A --> G[Damp Proof Course]
    G --> H[25 mm 1:2 Cement Mortar]
    G --> I[Bituminous Course]

This ensures durability and moisture resistance in foundation and basement masonry.

IS 2572: Key Specifications for Laying Concrete Block Masonry in Superstructure

1. Mortar Mix Proportions (Clause 6.9.2, Table 6.10)

2. Damp Proofing (Clause 10.1.2)

• Use richer mortar in damp soils (refer Table 1).
• Provide a damp-proof course (DPC):
  • 25 mm thick layer of 1:2 cement mortar, or
  • Approved bituminous course.

3. Laying Operation (Clause 11.2)

• Blocks must be laid with full mortar bedding.
• Maintain uniform joint thickness (usually 10 mm).
• Ensure proper alignment and leveling.
• Reinforcement (if used) should be placed as per design.

Summary:

• Use richer mortar mixes for reinforced or heavily loaded masonry.
• Provide DPC in damp conditions.
• Follow proper laying techniques for durability and strength.

flowchart TD
    A[Prepare Foundation & DPC] --> B[Mix Mortar as per Table 6.10]
    B --> C[Lay Blocks with Full Mortar Bedding]
    C --> D[Place Reinforcement if Required]
    D --> E[Check Alignment & Joint Thickness]
    E --> F[Curing and Finishing]

This ensures strong, durable concrete block masonry in superstructures per IS 2572.

IS 2572: Finishing and Waterproofing - Key Points & Specifications

Waterproofing Basement Walls (Clause 12.3)

• Plaster Thickness: 12 mm cement plaster (1:3 mix) in two coats.
• Application: Start just below ground line on outside wall, continue down and over footing edge.
• Wet Subsoil: Coat plaster with asphalt for additional waterproofing.
• Maintenance: Annual inspection before monsoon; seal cracks with cement grout and apply two coats of cement paint.

Finishing (Clause 11.5.2)

• Roof Course Finish: Smooth thin layer of 1:3 cement mortar.
• Protection: Cover with crude oil, craft paper, or oil paper for free roof movement.

Material Handling (Clause 8.2)

• Store and handle cement, lime, aggregates per relevant IS standards (e.g., IS 4082).

Quick Reference Table: Waterproofing Plaster Mix

Diagram: Waterproofing Application on Basement Wall

graph TD
A[Ground Level] --> B[12 mm Cement Plaster (1:3)]
B --> C[Plaster continues down wall]
C --> D[Plaster extends over footing edge]
D --> E[Asphalt coating if wet subsoil]

References:

• IS 2572 Clause 12.3, 11.5.2, 8.2
• Related IS codes: IS 4082 (material handling), IS 1542 (sand for plaster)

IS 2572: Inspection and Quality Control - Key Points

1. Inspection for Continuous + Tension & Shear (Clauses 2.8, 4.2)

• Visual Inspection: Check for continuity of reinforcement and proper anchorage.
• Tension & Shear Checks: Ensure reinforcement bars are free from rust, properly placed, and anchored to resist tension and shear forces.
• Testing: Conduct tensile tests on reinforcement bars as per IS 432 (Part 1):1982.

2. Quality Control Specifications

• Use materials conforming to relevant IS standards (refer below).
• Maintain vertical metal anchors (C.I. 32×6 mm) spaced at 1.2 m vertically with 50 mm embedment.
• Use elastic joint sealants for flexible connections (Fig. 12) to accommodate movements.

3. Reference Indian Standards for Materials & Methods

4. Typical Inspection Checklist

• Verify material certificates per IS standards.
• Check reinforcement spacing and cover.
• Confirm proper anchorage and continuity.
• Inspect flexible connections for intersecting walls.
• Ensure site storage and stacking as per IS 4082:1996.

Summary Table: Inspection Parameters

flowchart TD
    A[Material Procurement] --> B[Inspection of Materials per IS Codes]
    B --> C[Reinforcement Placement Check]
    C --> D[Anchorage & Continuity Verification]
    D --> E[Flexible Connection

IS 2572: Structural Design & Working Stresses - Key Points

Working Stresses (Clause 2.1)

Applied and induced stresses (on net area) in unreinforced concrete masonry shall not exceed:

Slenderness Reduction (Clause 2.5)

• Stresses must be reduced based on slenderness ratio to prevent buckling or instability.
• Reduction factors depend on component geometry and support conditions (refer IS 2572 detailed tables).

Load Distribution (Clause 1.2.2)

• Load distribution should consider relative rigidities.
• Structural separations allowed if no damage from deformation or displacement occurs.

Related IS Codes for Design Loads & Materials

• IS 875 (Parts 1-5): Design loads (dead, imposed, wind, snow, special loads)
• IS 456: Plain and reinforced concrete design
• IS 1905: Structural use of unreinforced masonry
• IS 2185: Concrete masonry units

Summary Diagram: Stress Limits in Masonry

flowchart TD
    A[Applied Stresses] --> B{Inspection Type}
    B -->|Continuous| C[Max Compression: 4.2 kg/cm²]
    B -->|Continuous| D[Compression + Tension/Shear: 0.7 kg/cm²]
    B -->|Without Continuous| E[Max Compression: 2.8 kg/cm²]
    B -->|Without Continuous| F[Compression + Tension/Shear: 0.4 kg/cm²]

Note: Always verify slenderness effects and use relevant IS codes for load combinations and material specifications.

IS 2572: Prevention and Control of Cracking in Hollow Concrete Block Walls

Key Points from Clause 7.4.3.1 (Moisture Movement)

• Moisture Content Limits:

  • Use blocks with moisture content ≤ 40% of max water absorption if ambient relative humidity (RH) ≥ 60%.
  • Use blocks with moisture content ≤ 25% of max water absorption if RH < 60%.

• Control Joints for Shrinkage:

  • Provide control joints at intervals of:
    • 8 to 10 m in free unsupported walls/partitions.
    • 15 to 18 m in walls connected by cross walls.
  • Also provide joints at:
    • Junctions of load-bearing and non-load-bearing walls.
    • Junctions of columns and partitions.

Control Joint Design (Summary)

Additional Measures (from IS 2572 & related IS codes)

• Use metal anchors (e.g., C.I. 32×6 mm) with vertical spacing of 1.2 m and embedment of 50 mm for flexible connections (see Fig. 12 in IS 2572).
• Use elastic joint sealants at control joints to accommodate movement.
• Ensure proper curing and use quality materials per referenced IS codes (e.g., IS 269, IS 2185, IS 456).

Summary Diagram: Control Joint Placement in Walls

graph LR
A[Load Bearing Wall] -- Control Joint --> B[Non-Load Bearing Wall]
C[Column] -- Control Joint --> B
D[Free Unsupported Wall] -- Joints every 8-10m --> E[Control Joints]
F[Wall with Cross Walls] -- Joints every 15-18m --> E

References:

• IS 2572: Clause 7.4.3.1
• IS 2185 (Part 1): Hollow and Solid Concrete Blocks
• IS 456: Code of Practice for Plain and Reinforced Concrete

Use these guidelines to minimize cracking due to shrinkage and moisture variation.