1. Dimension and tolerance test
2. Compressive strength test
3. Water absorption test
4. Efflorescence test
2. Compressive Strength Test:
(i) Take five bricks out of the sample at random.
(ii) Immerse the bricks in water at room temperature for 24 hours.
(iii) Fill the frags and all voids in the bed and face with cement mortar 1:1.
(iv) Store the bricks under damp gunny bags for 24 hours and thereafter immerse them in water for 72 hours.
(v) Place compression testing machine
(vi) Apply the load of a uniform rate of 140 kg/cm2 per minute till the brick foils
(vii) Take the average value of the comp. strengths of the five bricks.
(viii)The Compressive strength of a common brick should be 50 kg/cm2.
3. Water Absorption Test:
If the water absorption capacity of a brick is more, its strength will be comparatively low.
(i) Select ive bricks at random out of the given sample.
(ii) Dry them in a ventilated oven at 105 to 110C till they attain practically constant weight.
(iii) Remove the bricks from the oven and cool them to room temperature.
(iv) Weight the bricks in a balance. Let it be W1 kg.
(v) Immerse the five bricks in water completely at 27± 2C for 24 hours.
(vi) Remove one brick from water and wipe off its surfaces with a damp cloth.
(vii) Weight the brick within three minutes after its removal from water. Let its weight be W2 kg.
(viii)Water absorption capacity = (W2-W1/W1) x 100
(ix) Take the average value of the water absorption capacities of the five bricks.
(x) For 1st class bricks, the water absorption capacity should not be more than 20% by wt.
4. Efflorescence Test:
This test is performed to know the presence of any alkaline malter in the bricks.
(i) Take five bricks at random from the given sample.
(ii) Place each brick on end in a dish containing distilled water ensuring depth immersion at least 2.5 cm.
(iii)Keep the dish in a ventilated room (temp 20 to 30 C) till the whole of distilled water in the dish evaporates.
(iv) Again pore 2.5 cm depth of distilled water in the dish and keep it till whole of water gets evaporated.