Reinforcement detailing of Columns from ETABS output

• Detailing principle of RC Member as per the Code IS:456 and IS:13920 are as follows:

1.Minimum reinforcement for shrinkage & temperature

2. Ultimate limit state design rebar requirement

3.Ductility rebar requirement

The value from the above three having maximum area of the steel is taken for the design:

• Minimum longitudinal reinforcement as per IS-456-2000 clause 26.5.3.1[From the ETABS, As=2340mm2].
• Minimum shear (or) transverse reinforcement as per IS-13920-2016 clause-7.4.2- [8mm dia. at 300mm spacing].
• Development length as per IS-456-2000 caluse-26.2.1. [Ld= 41 x diameter of bar.]

Design of the Columns from ETABS:

Answer: Column Design 3A (450mmx600mm)

Steel reinforcement from the ETABS for the Flexure and Shear are as follows for the Column 3A

Steel reinforcement from the ETABS for the Flexure and Shear are as follows for the Column 3B:

Answer: Column Design 3B (450mmx600mm)

Storey assignment tab from ETABS:

Design of the column as per IS-13920-2016, Clause 8.1

The calculation of lo should not be less than as follows:

a) Larger column dimension

b)1/6 of the clear span of the column

c) 450mm

lo= 650mm(larger column dimension)

Confinement reinforcement spacing not more than

a)1/4 of smaller column dimension

b)6 times of dia of column main bar

c)100mm

Confining reinforcement spacing = 100mm

The amount of confinement rebar:

Ash= max of((a)0.18*sv*h*fck/fy((Ag/Ak)-1),(b)0.05*sv*h*fck/fy)) = 169mm2

Note: The column reinforcement details are in the attached file for your reference.