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

concrete-construction

NOTES: When both fine and coarse aggregates are poorly graded, the following general rules regarding suitable proportioning of these will be found helpful:
  1. For maximum size of coarse aggregates as 40mm and over, sand should be half as much as coarse aggregates.
  2. For maximum size of coarse aggregates as 20mm and over, sand should be two-thirds as much as coarse aggregates.
  3. For maximum size of coarse aggregates as 16mm, sand and coarse aggregates should be in equal parts.