Field Tests for Bricks

Field Tests for Bricks :

Field Tests for Bricks  generally  subjected  to  suitability of the construction work.

1. Absorption
2. Crushing strength or compression strength
3. Hardness
4. Presence soluble salts
5. Shape and size
6. Soundness
7. Structure

1)  Absorption: A good should not absorb not more than 20 percent of weight of dry brick

2)  Compressive  strength:  crushing  or  compressive  strength  of brick is found out by placing it in compression testing machine. It is  pressed  till  it  breaks.  Minimum  crushing  strength  of  brick  is Bricks  35kg/cm 2   and  for  superior  bricks,  it  may  vary  from  70  to  140 kg/cm 2 .

3)  Hardness:  No  impression  is  left  on  the  surface  the  brick  is treated to be sufficiently hard

4)  Presence of soluble salts: The bricks should not show any grey or white deposits after immerted in water for 24 hours

5)  Shape and size: It should be standard size and shape with sharp edges

6)  Soundness:  The  brick  should  give  clear  ringing  sound  struck each other

7)  Structure:  The  structure  should  be  homogeneous,  compact  and free from any defects

 

Grading of Bricks

As per IS10719557 and 1970 code specifications,

1. Bricks with  compressive  strength  not  less  than  140kg/cm2  – Grade A-A class.
2. Bricks with compressive strength not less than 105kg/cm2 – First class bricks – Grade A.
3. Bricks with  compressive  strength  not  less  than  70kg/cm2  – Second class bricks – Grade B.
4. Bricks with compressive strength not less than the average value 35kg/cm2 – class III bricks – Grade C.