The answer seems to be wrong. Concrete achieves 65% strength in 7 days. Characteristic compressive strength of M20 Grade Concrete is 20N/mm2. So 65% of 20 = 13N/mm2.

Anbarasan said:
(Dec 20, 2016)

Which is correct? @Barish Raut.

Prabhu said:
(Mar 13, 2017)

The Answer should be 15.

Chhaya said:
(Apr 20, 2017)

According to me, the Concrete achieve 66.666% strength So the answer is 13.24.

Roy said:
(Sep 9, 2017)

Yes, for M15 grade, it is 10 n/mm^2.

Chandrakant said:
(Aug 10, 2018)

67% is 70% approx.

Hence 14N/mm2 answer should be 15.

Manohar said:
(Aug 28, 2018)

According to me, the answer is 13.

Ankit Oza said:
(Mar 27, 2019)

In case of M20,

7th-day strength shall be:

20 * 0.65 = 13 N/Sqmm.

Rithu said:
(Jul 19, 2019)

It's 13.5 N/mm2.

Hasni said:
(Dec 28, 2019)

If it is 10 then concrete will achieve 50% strength in 07 days which is wrong it should be 15.

Mansha Bomb said:
(Jan 5, 2020)

It should be 65% of 20N/mm2 i.e. 13N/mm2.

Emad Nayef said:
(Feb 13, 2021)

The maximum compressive strength on 15 cm cubes of M 20 grade concrete at 7 days must be min 13.5, so the nearest answer is 15 (C).

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