IS Classification of Bricks
The BIS has categorized the bricks into HI, HII, FI, FII, I, II, LI and LII categories, primarily according to the compressive strength. Table 2 provides the BIS classification of bricks.
Table : BIS Classification of Bricks
|
Class of Bricks
|
Minimum Compressive Strength (kg/cm2)
|
Minimum Absorption in 24 Hours in Percent of Dry Weight
|
Efflorescence
|
Tolerance in Dimensio n in Percent
|
Shape and Other
Properties
|
|
HI
|
440
|
5
|
No
|
± 3
|
Metallic sound, smooth, rectangular
|
|
HII
|
440
|
5
|
No
|
± 8
|
Slight deformation in shape
permitted.
|
|
FI
|
175
|
12
|
Very little
|
± 3
|
Smooth, rectangular, metallic sound when two bricks strike.
|
|
FII
|
175
|
12
|
Very little
|
± 8
|
Slight deformation in shape permitted
|
|
I
|
70
|
20
|
Very little
|
± 3
|
Smooth, rectangular, metallic sound when two bricks strike.
|
|
II
|
70
|
20
|
Very little
|
± 8
|
Slight deformation in shape permitted
|
|
LI
|
35
|
25
|
Very little
|
± 3
|
Rectangular, sharp edge, metallic sound on striking need not be
present
|
|
LII
|
35
|
25
|
Little
|
± 8
|
Slight deformation in shape allowed.
|
In common bricks might be categorized within five categories
(1) First class bricks
(2) Second Class bricks
(3) Third Class bricks
(4) Over burnt or Jhama bricks
(5) Under burnt or killa bricks
Certain tests are essential to be conducted for judging the quality of a brick lot. These tests are:
(1) Water absorption test
(2) Test for presence of soluble salts
(3) Crushing strength test
(4) Hardness test
(5) Shape and size test
(6) Soundness test