RECOMMENDED CONCRETE MIXES FOR VARIOUS CONSTRUCTION
RECOMMENDED CONCRETE MIXES FOR VARIOUS TYPES OF CONSTRUCTION WORKS:
Type of work
|
App. Concrete Mix
|
Max. size of aggregates (mm)
|
Water for one cement bag batch (ltr)
| ||
Total for dry aggregates
|
For aggregates condition from dry to moist
|
Best consistency
| |||
Small precast work, fence posts, poles, garden furniture and other work of very thin sections
|
1:2:2
|
16
|
20
|
15 to 16
|
Soft
|
Storage tanks, cisterns, sewers, well knerbs, watertight work, and columns or other structural parts subjected to high stresses
|
1:2:3
|
20
|
25
|
19 to 22
|
Medium
|
Reinforced concrete work, floor slab, beams, columns, arches, stairs etc
|
1:2.5:3.5
|
20
|
32
|
23 to 27
|
Medium or soft
|
Ordinary floors, footpaths, drive ways, steps, roads, pavements
|
1:2.5:3.5
|
20
|
23
|
20 to 23
|
Stiff
|
Building and basement walls, silos, sills, lintels, machine foundations subject to vibration, bridges, dams, piers, etc exposed to action of water and frost foundation concrete for masonry walls
|
1:2:4
|
40
|
30
|
23 to 26
|
Stiff or Medium
|
Culverts, retaining walls, compound walls, ordinary machine bases, etc.
|
1:3:5
|
40
|
34
|
26 to 30
|
Stiff or Medium
|
Mass concrete for heavy walls, lean concrete for levelling course of RCC foundations
|
1:3:6
|
63
|
36
|
30 to 32
|
Medium
|
NOTES: When both fine and coarse aggregates are poorly graded, the following general rules regarding suitable proportioning of these will be found helpful:
- For maximum size of coarse aggregates as 40mm and over, sand should be half as much as coarse aggregates.
- For maximum size of coarse aggregates as 20mm and over, sand should be two-thirds as much as coarse aggregates.
- For maximum size of coarse aggregates as 16mm, sand and coarse aggregates should be in equal parts.
