How to Check the Strength of the Brick at Site?

Bricks are of two sizes ;

• Modular bricks : 19cm *9cm * 9cm (actual size )
• Non modular size : 20 cm* 10 cm* 10 cm ( commonly used; size of bricks with mortar )

1. When two bricks are striked against each other it Should produce clear ringing sound. This brick is known to have sufficient soundness and without crack.
2. When a brick is dropped from certain height of 1m on a levelled surface it shouldn’t be broken down in to pieces which depicts the toughness of the brick.
3. When a scratch is made on the surface of the brick ; any impression on the nail shouldn’t be produced.
4. Minimum strength of the brick used in construction work should be 3.5 N/mm^2
5. A first class brick should have water absorption is less than 20% otherwise it will absorb water from mortar causes crack in it.
6. A good quality brick should be of high temperature resistance. According to this properties;

• Heavy duty brick : 1450°C – 1650°C
• Medium duty brick : 1000°C – 1400°C
• Low duty brick : 850°C .

The bricks may contain harmful ingredients like alkalies, excess magnesia and excess lime. To know these values we have to do lab tests.

This is a common building construction material. Nowadays concrete bricks are taking the place of traditional bricks.

Traditional bricks are used for two types of walls. The testing of brick is the same for its uses in any type of wall.

1. Partition wall
2. Load-bearing wall

Following are the site tests to check the good quality of bricks:

1. Edges of bricks should be sharp and the surface should be scratch resistant.
2. All the bricks are of the same size
3. Bricks must have a size of standard brick i.e 19 cm X 9 CM x 9 CM. To check the length breadth and height take randomly 20 bricks and observe its edges.
4. A good brick should have a bright and uniform color.
5. soundness test on brick: select 2 random bricks and stuck with each other so that the clear and ringing bell sound must be produced. It indicates a good and strong brick.
6. Structure and material of bricks: select any randomly break and crack it from the middle then observe the inner portion. It must be free from any type of lumps and materials compacted homogeneously.
7. Efflorescence test: Bricks must be free from any types of salts. Take a brick and placed it in water for 24 hours. Take the brick out and dry it in a shade. After some time of drying if any white substance produced on the brick it indicates the amount of salt present inside bricks. This type of bricks must be avoided for construction

Some methods are followed to test the brick strength at site are as follows :-

1. The good brick should well burned with uniform shape and colour, free from cracks and the colour of the brick is red or copper with homogeneous texture.

2. The brick should be square, straightand sharply defined edges.

3. The brick should be hard when strucked each other it should gives metallic ringing sound.

4. It should not brake while stacking each other or droped from height about 4feet on to the ground.

5. The brick after emersion on water for 1 hour the water absorption should not be more than 15% of its weight.