## Minimum and Maximum reinforcement for tanks

**Minimum and Maximum Reinforcement details in Tanks
**

**Minimum Reinforcement**

(a) The minimum reinforcement in walls, floors and roofs in each of two directions at right angles shall have an area of 0.3 per cent of the concrete section in that direction for sections upto 100 mm, thickness. For sections of thickness greater than 100 mm, and less than 450 mm the minimum reinforcement in each of the two directions shall be linearly reduced from 0.3 percent for 100 mm. thick section to 0.2 percent for 450 mm, thick sections. For sections of thickness greater than 450 mm, minimum reinforcement in each of the two directions shall be kept at 0.2 per cent. In concrete sections of thickness 225 mm or greater, two layers of reinforcement steel shall be placed one near each face of the section to make up the minimum reinforcement.

(b) In special circumstances floor slabs may be constructed with percentage of reinforcement less than specified above. In no case the percentage of reinforcement in any member be less than 0°15% of gross sectional area of the member.

The detailing of reinforcement for flexure members are provided in general ACI 350-06 section 10.5.1:

walls have an additional criteria to meet, ACI 350-06 section 14.3.2:

Also, see ACI 350-06 section 7.12.2.1 for minimum steel requirements for shrinkage and temperature

There does not appear to be a maximum steel limit in ACI 350-06, as there is in ACI 318. However, it may be good to include it in the design.

**ACI 318-89 section 10.3.3:**