• How to Determine the Compressive test of Bricks

    by  • December 15, 2013 • Articles, concrete, Practicles • 1 Comment

    To determine the Compressive strength of bricks

    Apparatus
    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.

    Compression testing machine

    Compression Testing Machine

    Fig: Compression Testing Machine

    Specimens
    Three numbers of whole bricks from sample collected should be taken .the dimensions should be measured to the nearest 1mm

    Sampling
    Remove unevenness observed the bed faces to provide two smooth parallel faces by grinding .Immerse in water at room temperature for 24 hours .Remove the specimen and drain out any surplus moisture at room temperature. Fill the frog and all voids in the bed faces flush with cement mortar (1 cement,1 clean coarse sand of grade 3mm and down). Store it under the damp jute bags for 24 hours filled by immersion in clean water for 3 days .Remove and wipe out any traces of moisture.

    Procedure
    (I) Place the specimen with flat face s horizontal and mortar filled face facing upwards between plates of the testing machine.

    (II) Apply load axially at a uniform rate of 14 N/mm(square) per minute till failure occurs and note maximum load at failure.

    (III) 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 :

    Compressive Strength = Maximum load at failure / Average Area of Bed face.

    The average of result shall be reported.

    Range Calculation

    Maximum compressive strength =

    Contact area =

    Maximum expected load =

    The range to be selected is …………………

    Result

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

    IS SPECIFICATIONS

    Speciation of Common Clay Building Bricks

    Dimensions: The standard size of clay bricks shall be as follows

    Length (mm)

     

    Width (mm)

     

    Height (mm)

     

    190 90 90
    190 90 40

     

    Classification: The common burnt clay shall be classified on the basis of average compressive strength as given in table.

    Class Designation

     

                                         

     

    Average compressive strength

     

    Not less than

     

    ()

     

    Less than

     

    ()

     

    350 35 40
    300 30 35
    250 25 30
    200 20 25
    175 17.5 20
    150 15 17.5
    125 12.5 15
    100 10 12.5
    75 7.5 10
    50 5 7.5
    35 3.5 5