Abrahm's law of water-cement ratio - Mathematical relation and graph

 Abrahm's law expresses the relation between compressive strength of concrete mix and the water-cement ratio which is taken in designing concrete mix.

  This law states that the compressive strength of concrete mix is inversely related to its water/cement ratio.

    If water/cement ratio (w/c ratio) increases, the strength of concrete decreases. He presented his classic law as :-

S = A/B*

where, S = compressive strength of concrete mix

            * = water/cement ratio

            A and B are constants. 

The graph showing the relation between the strength and w/c ratio of the concrete mix is approximately hyperbolic shape.


    The graph says, lower w/c ratio is taken when the concrete is vibrated for compaction and higher w/c ratio is required for hand compaction of concrete.

  If we draw a line graph to show the relation between strength and c/w ratio , it shows approximately a linear relationship.



Thank you.

Gracious !

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