Various types of concrete construction requires different concrete indexs for its construction. The recommended value of these concrete mixes for various types of construction is presented in table below:
Type of work | Concrete Mix Ratio | Max. size of aggregates (mm) | Water for dry aggregates (liter)* | Water for aggregates condition from dry to moist batch (liter)* | Water for best consistency (liter)* |
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 |