SPECIFICATION FOR COMPRESSIVE STRENGTH CLASSIFICATION OF BUILDING BRICK (IS: 1077)

COMPRESSIVE STRENGTH CLASSIFICATION OF BUILDING BRICK

According to the Bureau of Indian Standard the brick are classified on the basis of compressive strength.

IS CLASSIFICATION (IS-1077)

        class   average compressive strength not less than(N/mm2) 

        1)  3.5                         3.5

        2)   5                            5

        3)  7.5                          7.5

        4)  10                           10

        5)   12.5                       12.5

        6)   15                          15

        7)   17.5                       17.5

        8)   20                           20

        9)   25                           25

       10) 30                            30

       11)  35                           35

• burnt clay brick having compressive strength more than 40.0 N/mm2 are known as heavy duty bricks and are used for heavy duty structures such as bridge, foundation, industrial building, multistory buildings, etc. the water absorption of these bricks are limited to 5% of it dry weight.

• each class of brick as specified above are further divided into subclasses A and B based on tolerance and shape. subclass A bricks should have smooth rectangular shapes with sharp corners and uniform colour. subclass B bricks may have slightly distorted and round edges.

         Subclass A Brick

                                         dimension               tolerance 

                                               (cm)                         (mm)

         length-                          380                 12 mm ( less or more)

         width-                           180                   6 mm  (less or more)

        height- 1) 9 cm             180                    6 mm (less or more)

                     2) 4 cm               80                     3 mm (less or more)

    

          Subclass B Brick

                                        Dimension                Tolerance

                                             (cm)                       (mm)

            Length                       380                30 (less or more)

             Width                       180                 15 (less or more)

           Height- 1) 9 cm         180                 15 ( less or more)

                       2) 4 cm            80                   6  (less or more)