Testing Bricks at Site | Quality of Clay Bricks | Visual and Experimental Tests for Quality Bricks

Bricks are basic building blocks of masonry work and construction material for load bearing walls, partition walls, and other elements of buildings. Basically, bricks are made of naturally available material like clay, aggregate, sand and other mixtures like concrete. There are various types of quality bricks available in the market based on location, type & size.

Bricks are placed in various courses and number of patterns known as bonds which is collectively known as brickwork, and may be placed in various kinds of mortar layers (Cement/Fly ash/ Lime) to hold the bricks together to make it strong and solid durable structural element.

Uniform Copper coloured clay Bricks
Uniform Copper coloured clay Bricks

In order to form a solid structure, the quality of brick is very important. To ensure this, quality of brick may be assessed using various kinds of tests. The tests are carried out in both field as well as in the laboratory.

Tests for Quality bricks

In this article, I have explained various kinds of visual as well as experimental tests that are used to assess the quality of bricks, especially clay bricks. These tests are very useful for Site Engineer and Supervisors to assess the quality of bricks being used at site easily.

  1. Color Test
  2. Shape Test
  3. Struck Test
  4. Scratch Test
  5. Transit and stacking Test
  6. Water Absorption Test
  7. Efflorescence Test
  8. Dropping Test

Color Test:

Good quality bricks are always uniform in color throughout its entire surface. Well burnt bricks are always copper color. In a lot, you can take the sample of the bricks and see its color on all sides, if it is copper color and uniform it is quality one. See the copper color of brick in image above.

Shape Test:

For Shape test, take at least 10 samples of bricks from a lot and check if their length, breadth & width are uniform and it must not vary from brick-to-brick for the quality bricks.

Struck Test:

For struck test, take 2 bricks and strike each other along the longer edge. If it produces metallic or Ring bell sound, the bricks are quality bricks.

Two bricks are Two bricks are Struck each otherStruck each other
Two bricks are Struck each other

Scratch Test:

When bricks are scratched by iron nail it does must produce any impressions on the surface, these bricks are quality bricks. 

No scratch on the surface of brick
No scratch on the surface of brick

Transit and stacking Test:

When bricks are transported or stacked in ordinary handling, the percentage of broken bricks should below 3%. For example when we transit and stack 1000 bricks, the broken no’s of bricks should be below 30. If it’s exceeds 30 the bricks quality must be considered poor.

Water Absorption test: 

When bricks are immersed and soaked in water for 24 hours the water absorption should be below 20%.

For example:-

Initial weight of brick W1 = 4.10 Kg.

After 24 hrs immersed in water the weight of brick W2 = 4.25 kg.

Water absorption = ((W2-W1)/W1) x 100 = ((4.75-4.10)/4.10)*100 = 15.85%

So, the water absorption is 15.85% which is below 20%. Hence, these bricks are quality bricks.

Brick immersed in water for 24 Hrs
Brick immersed in water for 24 Hrs

Efflorescence Test for quality bricks :

When bricks are soaked in water and dried it must not develop white patches or white deposits on its surface. These bricks are considered good bricks. The phenomenon of formation of white patches is called efflorescence.

Bricks are soaked in water
Bricks are soaked in water

Dropping Test

When bricks are dropped from the height of 1 to 1.2m (4 feet), it should not crack or break. This ensures the durability and quality of bricks.

Brick dropped from the height of 1m
Brick dropped from the height of 1m