Compressive strength of bricks

Dnyan Deshmukh

Staff member
Compressive strength of bricks

Ref : IS : 3495 (part I) – 1992

Purpose : To determine the compressive strength of bricks

Salient features:

a) Compression testing machine

b) The compression plate, which shall have a ball seating in the form of portion of a sphere, the centre of the plate, shall be used

Preparation of sample:

  1. Grind the uneven bed faces to provide two smooth and parallel faces
  2. Immerse the sample in water at room temperature for 24 hours
  3. Remove the sample from water and drain out any surplus water at room temperature
  4. Fill the frog and all the voids in the bed face flush with cement mortar
  5. Store under the damp jute bags for 24 hours followed by immersion in clean water for 3 days
brick testing2.jpg

Test Procedure:

a) Place the sample with flat faces horizontal and mortar filled face facing upwards, between two 3mm thick plywood sheet and carefully centered between plates of testing

b) Apply load axially at a uniform rate of 14 N/mm2 / 140 Kgf/cm2 per minute till the sample fails

c) Note the maximum load at failure


Compressive Strength (N/mm2 / Kgf/cm2) = Maximum load at failure in N or Kgf divided by Avg. net area of two faces under compression in mm2 or cm2