Minimum Percentage of Reinforcement

The minimum percentage of reinforcement for beam, column and slabs can be found from the table 3.25 of BS 8110 Part 01 1997. You may refer to the following table to find the required reinforcement ratios.

According to the above table, we need to provide the minimum percentage of reinforcement for the section in each direction.

For example, consider a beam

Width of section 300 mm
Height of section 500 mm
Assume we provide deformed bars

According to the above table, the minimum percentage of reinforcements calculation is as follows.

100 As /Ac     = 0.13
As                   = 0.13xAc / 100
                       = 0.13x300x500 / 100
                       = 195 mm2

We need to provide at least this amount for the beam, so we can provide 2T12 for the beam.

Similarly, we can find the reinforcement requirements for other sections as well.