In mix design for M25 concrete, the assumed standard deviation for estimation of target mean strength of concrete mix, as recommended by IS 456: 2000 is (in N/mm2):

Question

RRB Paper · Accepted Answer

The target mean strength (f­m) is taken as fm = fck + 1.65 σ where, fck = characteristic compressive strength, and σ = standard deviation The standard deviation for different grades of concrete as per Clause 9.2.4.2 IS:456-2000 Sl. No Grade of Concrete Characteristic compressive strength (N/mm2) Assumed standard deviation (N/mm2) 1. M10 10 3.5 2. M15 15 3. M20 20 4.0 4. M25 25 5. M30 30 5.0 6. M35 35 7. M40 40 8. M45 45 9. M50 50 10. M55 55

In mix design for M25 concrete, the assumed standard deviation for estimation of target mean strength of concrete mix, as recommended by IS 456: 2000 is (in N/mm²):

3.5

4.5

4.0

5.0

The correct answer is `No. 3: 4.0`

Details

Frameworks

Database

Billing

Completed

Drop campaign files here or click to upload.

No result found

Advanced Search

In mix design for M25 concrete, the assumed standard deviation for estimation of target mean strength of concrete mix, as recommended by IS 456: 2000 is (in N/mm2):

3.5

4.5

4.0

5.0

The correct answer is No. 3: 4.0

In mix design for M25 concrete, the assumed standard deviation for estimation of target mean strength of concrete mix, as recommended by IS 456: 2000 is (in N/mm²):

The correct answer is `No. 3: 4.0`