Apparatus

1.      Three flooring type tiles

2.    Universal testing machine

3.    Scale

4.    Water tank

5.     Steel bars etc.


Diagram


Flexural Testing Machine



Theory

Cement concrete flooring tiles are becoming more popular material. Flooring material I.S. 1237-1980 has recommended.

Three standard size of square tiles.

1.      200 mm x 200 mm

2.    250 mm x 250 mm

3.    300 mm x 300 mm

For flexural test on tiles the tiles are tested in wet condition. They are supported on steel bar supporting varying surface on tiles. Tiles is kept upward. A central load is apply at the centre of tile with third bar. All the three bars have lense longer then the tile. Diameter of bar is 12 mm, load is gradually increase until the tile is break.

Flexural strength is calculated from formula

                               ∑ =     3 PL / 2 bt2


The average transerverse strength of six times shall be taken as result. I.S. 1237-930 specified that values should not be less than 3 N/mm2 or 30 kg/cm2. Steel bar supporting with wearing surface of tile upward.
Apply load through steel bar parallel to support at mid span of the length of supporting and loading bar should be longer than length of the tile and diameter should be 12 mm.
Apply load gradually at uniform rate not exceed 200 N/mm2, until the tile break.


Calculation

W = Before saturation wt = 2 kg

W1 = After saturation wt = 3 kg = 300 gms

P = 9150 gm

q = 250 mm

u = 250 mm

t = 20 mm


FLEXURAL STRANGTH

    ∑ = 3 PL / 2 bt2

        = 3 x 9.150 x 250 x 10 / 2 x 250 x (20)2

             = 0.342 N/mm2



    ∑  = 3 PL / 2 bt2

        = 3 x 11.717 x 250 x 10 / 2 x 250 x (20)2
       
        = 0.44 N/mm2
      


Result

Average flextural strength

Class
Flextural strength
A-A
0.343 N/mm2
B
0.44 N/mm2



Conclusion

As the tile does not conform the I.S. code 1237 – 1980. It is not of good qualities belong to class ‘A’
http://www.labnol.org/