Perforated Bricks Compressive Strength As Per IS Code

Civil Engicon Team
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Update: May 23, 2023

What is a Perforated Brick?

Perforated brick is a type of brick masonry unit that having a pattern of holes or perforations throughout the brick. The holes in the brick provide several benefits like reducing the weight of the brick, improving ventilation and drainage and increasing thermal insulation properties of bricks.
These bricks are commonly used in construction of walls, foundations and other structures. They come in various sizes, shapes and colors, and it can be made from a variety of materials such as clay, concrete or natural stone.
The size and pattern of the perforations can vary depending on the intended use of the bricks. 
For Example: Bricks with larger perforations may be used for load-bearing walls to reduce the weight of the structure while bricks with smaller perforations may be used for non-load bearing walls to improve ventilation and drainage.

Perforated Bricks Compressive Strength Test As Per IS Code Book

The compressive strength of perforated bricks can be tested as per given below standard procedure.

Perforated Bricks Compressive Strength Test As Per IS Code

Standard Procedure Perforated Bricks Compressive Strength

Indian Standard Used

  • IS: 5454 - 1978 [Method for Sampling of Clay Bricks]
  • IS: 3495 (Part 1) - 1992 [Method of Test of Burnt Clay Building Bricks]
  • IS: 2222 - 1991 [Specification For Burnt Clay Perforated Building Bricks]

General Requirements for Testing

  • The dimensions of the bricks shall be measured to the nearest 1 mm.
  • All apparatus and testing equipment shall be calibrated at frequent intervals.
  • The number of specimens for the test shall be selected as per IS: 5454 - 1978.

Perforated Bricks Compressive Strength As Per IS Code

Apparatus Required

  1. Compression Testing Machine [C.T.M.].
  2. Measuring Tape [Least Count 1 mm].
  3. Plywood or Plaster or Paris [3 mm Thick].

Formula Used

Compressive Strength (N/mm²)= [Maximum Peak Load (N)/ Average Net Area of Perforated Faces (mm²)]

Note:- ''Peak Load'' is also known as ''Maximum Breaking Load' or ''Maximum Load at Failure'' 

Only For Perforated Bricks


Step 1: Measure the perforated faces with measuring tape and note its average net area.
Step 2: Immerse the specimens in water at room temperature for 24 hours. 
Step 3: Remove all the specimens and drain out any surplus moisture. 
Step 4: Mortar will not be filled in perforations and also mortar capping will not be provided.  

Test Procedure For Perforated Bricks

Step 5: Place the perforated faces of bricks two 3-ply plywood sheets (each of 3 mm thick) and carefully centered between plates of the compression testing machine.
Step 6: Apply load axially at a uniform rate of 14 N/mm² (or 140 kgf/cm²) per minute till failure occurs and note the maximum load at failure. The load at failure shall be the maximum load at which the specimen fails to produce any further increase in the indicator reading on the testing machine. Repeat the ''Step 6'' for rest specimens. 

Note:- In place of plywood sheets, plaster of Paris may be used to ensure a uniform surface for the application of load.

Test Result

Compressive Strength of Bricks after 24 hours immersed in water at room temperature,

Compressive Strength (N/mm²)= [Maximum Peak Load (N)/ Average Net Area of Perforated Faces (mm²)]

Test Report

The average of results obtained from each specimen shall be reported as:
Compressive Strength (N/mm²)= ......

Requirements of The Compressive Strength of Perforated Bricks

As per IS: 2222 - 1991 [Specification For Burnt Clay Perforated Building Bricks], The brick test accordance with the procedure given in IS: 3495 (Part-1)- 1992, shall have a minimum average compressive strength of 7 N/mm² on net area.

Table For Checking Class Designation of Bricks

The compressive strength of any individual brick tested shall not fall below the min. compressive strength specified for the corresponding class of brick. The lot shall be then checked for the next lower class of bricks.


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