Civil Engineering - Concrete Technology - Discussion

Finer sand required more water so Answer D is correct.

GRADING LIMITS FOR FINE AGGREGATES.

Sieve Size Percentage of Passing For,
Grading
Zone-I

Grading
Zone-II

Grading
Zone-III

Grading
Zone-IV

10 mm 100 100 100 100
4.75 mm 90 " 100 90 " 100 90 " 100 95 " 100
2.36 mm 60 " 95 75 " 100 85 " 100 95 " 100
1.18 mm 30 " 70 55 " 90 75 " 100 90 " 1000
600 micron 15 " 34 35 " 59 60 " 79 80 " 100
300 micron 5 " 20 8 " 30 12 " 40 15 " 50
150 micron 0 " 10 0 " 10 0 " 10 0 " 15

Zone-I represents the coarse sand and zone-IV represents the finer sand in all the four zones. Hence correct answer should be D.

In this questions the correct answer in the D.

Surface area is more then w/c is the more and zone 4 not used for engineering works.

Since finer sand has the more specific surface area, and hence it will require more water to lubricate it.

Zone 4 correspond to fine aggregates, D is the correct answer.

Yes. Agree 4 should be the answer.

4 is the 100% correct one because of the max surface area.

Zone 4 sand is more fine. And more fine sand has more surface area. It requires more water. So the answer is zone 4.

Courser sand should require less area because less surface area.

Zone 1 is coarser and zone 4 is finer sand. It can be analysed by the sizes of the particle. Since the surface area is large in zone1, it requires more w/c.

How to categorize the sand that whether it is from zone-1 or from an other zone, just by seeing it physically, without conducting any test or analysis? Any one can explain?