HOW TO PERFORM COMPRESSIVE STRENGTH TEST OF BRICKS (IS-3495 (PART-1)) ?

COMPRESSIVE STRENGTH TEST OF BRICKS (IS-3495 (PART-1))

OBJECTIVE

To determine the compressive strength of bricks

EQUIPMENTS

• Compression testing machine :

Compression testing machine ,the compression plate of which shall have ball seating in the form of portion of a sphere center of which coincides with the centre of the plate.

• Steel Tape :

SPACIMENS

Six bricks are taken for the compressive strength test althought it may be found that an individual brick varies by 20% or more from the average, the permissible stresses allowed for load bearing walls take account of this, being based on an average strength of six bricks.

SAMPLING

For testing bricks for compressive strength from a sample the two bed faces of bricks are ground to provide smooth, even and parallel faces. The bricks are then immersed in water at room temperature for 24 hours. These are then taken out of water and surplus water on the surfaces is wiped off with. The frog of the brick is flushed level with cement mortar and the brick is stored under damp jute bags for 24 hours followed by its immersion in water at room temperature for 3 days.

PROCEDURE

• The specimen is placed in the compression testing machine with flat faces horizontal and mortar filled face being upwards.

• Load is applied at a uniform rate of 14 N/m2 per minute till failure.

• The load at failure is maximum load at which the specimen fails to produce any further increase in the indicator reading on the testing machine.

CALCULATION

The average of results shall be reported. The compressive strength of any individual brick tested in the sample should not fall below the minimum average compressive strength specified for the corresponding class of brick by more than 20 percent.

                                                       

RESULT

Average compressive strength of the given bricks =…………..