what should be the strength of Concrete cube strength for 7
days, if the designed mix is M20?
Answers were Sorted based on User's Feedback
Answer / viki
generally concrete attains 60-70% of its 28 days strength
in 7 days.After 28 days strength of M20 concrete will be
20N/mm2.so after 7days it would be 12-14 N/mm2.
Is This Answer Correct ? | 113 Yes | 28 No |
Answer / n.c.pathan
Concrete does attain strength of about 65% after a period
of 7 days. With good quality of cement nowadays available
we generally get better results. Many a times strength
exceeds 70% of 20N/SQ MM.
Is This Answer Correct ? | 27 Yes | 10 No |
Answer / g.mugesh
Grade of concrete:m20
7days test (67.5%) - 20*67.5/100=13.35 N/MM2
28days test(100%) - 20 N/MM2
Is This Answer Correct ? | 19 Yes | 10 No |
Answer / himanshu sekhar pradhan
Actuall all grade of concrete design upon its target
strength. Then for M20 we have to design the mix on
26.6N/mm2 and all grade of concrete should achive its 60 -
75% strength in 7days. Then the actual strength of M20
grade of concrete at 7days should be 17 -20 N/mm2.
Otherwise there is chance of fail.
Is This Answer Correct ? | 11 Yes | 4 No |
Design mix is M20 So Target strenth is Fck+4 = 24N/MM2
For 7 Days Cube strenth is 16.24 Exact (7days@67.67%)
For Individual Cube strenth become is Fck-3 = 13.24
But Average Sternth is required is 16.24 (must)
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Is This Answer Correct ? | 10 Yes | 6 No |
Answer / sathish
Actually concrete attains 64-70% of its 28 days strength
in 7 days.After 28 days strength of M20 concrete will be
20N/mm2.so after 7days it would be 12.80 -14.00 N/mm2.
Is This Answer Correct ? | 8 Yes | 5 No |
Answer / nithin
Is there any reference to 7 day strength in is codes.
Is This Answer Correct ? | 4 Yes | 1 No |
Answer / sandeep
If grade of concrete is M20
Then after 7 days it will be 2/3 of 20 n/sq mm
Means 0. 666*20 = 13. 20 n/sq mm
Is This Answer Correct ? | 1 Yes | 0 No |
Answer / devendra jatav
7 days - 70 to 75% strength
28 days - 100% strength
Is This Answer Correct ? | 0 Yes | 5 No |
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