Civil Engineering - Concrete Technology - Discussion

Discussion Forum : Concrete Technology - Section 1 (Q.No. 29)
29.
If 20 kg of coarse aggregate is sieved through 80 mm, 40 mm, 20 mm, 10 mm, 4.75 mm, 2.36 mm, 1.18 mm, 600 micron, 300 micron and 150 micron standard sieves and the weights retained are 0 kg, 2 kg, 8 kg, 6 kg, 4 kg respectively, the fineness modulus of the aggregate, is
7.30
7.35
7.40
7.45
none of these.
Answer: Option
Explanation:
No answer description is available. Let's discuss.
Discussion:
44 comments Page 3 of 5.

Moreri said:   9 years ago
Why do we divide 740 by 100?

Dangerous said:   9 years ago
Sieve Retained Reained perce Cumaltive size
80 0 0 0

40 2 10 10

20 8 40 50

10 6 30 80

4.75 4 20 100

2.36 0 0 100

1.18 0 0 100

600 0 0 100

300 0 0 100

150 0 0 100
740
Fineness modulus =740/100,
= 7.4.

HARSHA G said:   9 years ago
SIEVE WEIGHT RET CUMULATIVE WT CUM.%
SIZE
80 0 0 0
40 2 2 10
20 8 10 50
10 6 16 80
4.75 4 20 100
2.36 0 20 100
1.18 0 20 100
600M 0 20 100
300M 0 20 100
150M 0 20 100


ADD CUM % RET AND DIVIDE BY 100 740/100 = 7.4.

Fineness modulus is an empirical factor obtained by adding the cumulative percentages of aggregate retained on each of the standard sieves ranging from 80 mm to 150 micron and dividing this sum by 100.

CUM% = (CUM WT / TOTAL WT )* 100.

Virendra kumar said:   8 years ago
How to total 740 and what is 740? please explain.

Kavita said:   8 years ago
@ALL.

Please, Refer Is code 2386.

Pranit Vitekar said:   8 years ago
Seive. Weight % weight. Cumulative % wt
size. Retained retained. Retained
80. 0. 0. 0
40. 2 10. 10
20. 8 40. 50
10. 6 30. 80
4.75. 4 20. 100
2.36. 0. 0. 100
1.18. 0 0 100
600. 0 0 100
300. 0 0 100
150. 0. 0 100

Total cumulative % weight retained= 740.
Fineness modulus = total cumulative % weight retained/ 100.
FM=740/100.
7.40 is the correct answer.

Ritesh said:   8 years ago
Please explain this. I can't understand,

How get 740?

Kavita said:   8 years ago
Please explian clearly.

Priyanka said:   8 years ago
How to get 7.40?

Rahul said:   7 years ago
The fm of coarse aggregate is C+500/100.
The fm of fine aggregate is f/100.

So, what we try on sieve 4.75 lower all are fine particles as per code.


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