This document describes an experiment to determine the compressive strength of bricks. The experiment involves taking 5 bricks, grinding them to provide smooth parallel faces, immersing them in water for 24 hours, filling any voids with cement mortar, and allowing to cure for 24 more hours. The bricks are then placed between plywood sheets in a compression testing machine and loaded at a uniform rate until failure. The maximum load at failure is recorded as the compressive strength of the bricks. Proper testing of compressive strength is important because it determines the thickness of brick walls in construction.

1. EXPERIMENT NO: II
COMPRESSIVE STRENGTH OF BRICKS
By: Er. Sonia Verma
Gold Medalist
(M.Tech, Structural Engineering)
95926-99627, soneyamittu@gmail.com

2. AIM
To determine compressive strength of bricks.

3. APPARATUS
A compression
testing machine,
scale, plywood
cover

6. THEORY
 Bricks are mostly subjected to compression and
rarely to tension.
 The usual crushing strength of common hand
moulded well burnt bricks is @ 5 to 10 N/mm2
varying according to the nature of preparation of
clay pressed and machine moulded bricks made of
thoroughly pugged clay are much stronger than
common hand moulded bricks made from
carelessly prepared clay.
 In all the brick walls the compressive strength of
bricks decides the thickness of walls hence it is
necessary to test the compressive strength of the
bricks.

7. PROCEDURE
1. Take 5 bricks and remove unevenness observed
in the bed face to provide two smooth and parallel
faces by grinding.
2. Immerse the bricks in water at room temperature
for 24 hours
3. Remove the specimen and drain out any surplus
moisture at room temperature
4. Fill the frog (where provided) and all voids in the
bed face flush with cement mortar ( 1 cement, 1
clean coarse sand of grade 3 mm and down.)
5. Store under the damp jute box for 24 hours

8. BRICKS IMMERSED IN WATER

9. FROGS FILLED

10. PROCEDURE CONTD…
6. Remove and wipe out traces of moisture and place the
specimen with flat faces horizontal and mortar filled
few facing upwards between two plywood sheet each 3
mm thickness and carefully centered between plates of
testing machine.
7. Apply load axially of uniform rate.
8. Note down the load at failure. That load shall be the
maximum load at which the specimen fails to produce
any further increase in the indicator reading on the
testing machine.
Note: In place of plywood sheets plaster of paris may
be used to ensure a uniform surface of application of
load