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Reinforced Cement Concrete

Compressive Strength of Concrete

Find the comp...

Question

Find the compressive strength below which 50% test results are expected to fall for M20 concrete

A

20

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B

26.6

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C

13.4

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D

30

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Solution

The correct option is B 26.6
50% Test results fall below mean compressive strength $f_{m}$

$f_{m} = f_{c k} + 1.65 σ$

$= 20 + 1.65 \times 4$

$= 26.6 M P a$

[M20 has $f_{c k} = 20 M P a$ and $σ = 4 M P a$ ]

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