Desirable Concrete Cover for slab, beam, column and footing

In reinforced concrete, the concrete covers means the minimum distance among the surface of embedded reinforcement and the exterior surface of the concrete. (defined by ACI 130).

Benefits of concrete cover

a. To safeguard the steel reinforced bars (rebar’s) from ecological impacts to get rid of corrosion.
b. To arrange thermal insulation that safeguards the reinforcement bars from fire.
c. To provide adequate embedding to reinforcing bars to allow them to be stressed devoid of slipping.

SLAB COVERING - Concrete not susceptible to weather:

1. 36 mm Ø bar and smaller
16 mm if precast
20 mm if cast-in-place

Concrete susceptible to earth or weather :-
1. 16 mm Ø bar and smaller
30 mm if precast
40 mm if cast-in-place

2. 19 mm Ø through 36 mm Ø
40 mm if precast
50 mm if cast-in-place

3. 40 mm Ø to 57 mm Ø
50 mm if precast

BEAM COVERING - Concrete not susceptible to weather

1. 40 mm from main reinforcement, ties, stirrups, spirals if cast-in-place
2. 20 ≤ d_b ≤ 40 main reinforcement if cast-in-place
3. 16 mm from ties, stirrups, spiral if precast

Concrete susceptible to earth or weather

Main Reinforcement

1. 36 mm Ø bar and smaller
16 mm if precast
20 mm if cast-in-place

2. 40 mm Ø to 57 mm Ø
30 mm if precast
40 mm if cast-in-place

COLUMN COVERING - Concrete not susceptible to weather

1. 40 mm from main reinforcement, ties, stirrups, spirals if cast-in-place
2. 20 ≤ db ≤ 40 main reinforcement if cast-in-place
3. 16 mm from ties, stirrups, spiral if precast

Concrete susceptible to earth or weather

Main reinforcement

1. 36 mm Ø bar and smaller
16 mm if precast
20 mm if cast-in-place

2. 40 mm Ø to 57 mm Ø
30 mm if precast
40 mm if cast-in-place

FOOTING COVERING: Least concrete cover for concrete cast against and permanently exposed to earth should be 75 mm.