Rcc column design is an important part of designing any building. The column is the main supporting structural member of any building.
Column: Column is defined as a compression member which has an effective length greater than its least lateral dimension.
Let’s the design of column with an example,
RCC Column Design Example
Example: Design of RCC column as per is 456 square short column subjected to axial services compressive load of 600 KN. The concrete used is M -20 and Steel Fe – 500. Draw reinforcement details. Provide 1 % steel. Take the factor of safety 1.5.
RCC Column Design
- Fck = 20 N/mm2
- Fy = 500 N/mm2
- Ag = Gross area of Column
- Area of Steel in concrete(Asc) = (1/100) x Ag
- Area of Concrete(Ac) = Gross area of column(Ag) – Area of steel(Asc) Ac = Ag – 0.01 Ag
- Ac = 0.99 Ag
- Pu = Axial load on Column (600 x 1.5) = 900 KN
- Pu = 0.4 fck x Ac + 0.67 x Fy x Asc (IS: 456 – 2000 P – 71)
- 900 x 103 = 0.4 x 20 x ( 0.99 Ag) + 0.67 x 500 x 0.01 Ag
- Ag = 79858 mm2
RCC Column Size Calculation
- Square Column, Size of Column = √(79858) = 282.59 mm
- Provide square column size = 285 mm x 285 mm
- Ag = Provided = (285 mm x 285 mm) = 81225 mm2
- Asc = Area of steel in concrete
- = 0.01 Ag = 0.01 x 81225 = 812.25 mm2
- Provide 8 nos. – 12 mm Dia. steel bar having
- Ast (Area of steel) = 905 mm2
- RCC Column Design
- Dia of lateral ties: (IS: 456 -2000 P – 49)
- (i) 1/4 x Dia. of larger bar = 1/4 x 12 = 3 mm
- (ii) 8 mm
- Provide larger of 2 values (Provide 8 mm dia. lateral ties)
- The pitch of Lateral Ties: (IS: 456 -2000 P – 49)
(i) Least lateral dimension = 285 mm
(ii) 16 x Dia of smaller bar = 16 x 12 = 192 mm
(ii) 300 mm
14. Provide smaller of 3 values (Provide Pitch = 190 mm)
Provide 8 mm Dia. lateral ties at 190 mm c/c
Read More: Load Calculation on Column, Beam, and Slab
RCC Column Design
Column Design Excel Sheet as per IS 456 Free Download
RCC Column Design Excel Sheet Click Below,
Column Design Excel Sheet – Download
Watch Video: Learn How To Use Column Design Excel Sheet
How to calculate RCC column size?
To calculate RCC Column size it is required to know the parameters such as factored load on the column, the grade of steel, and the grade of concrete. Put the known value of parameters in the factored load formula. Factored load formulas are useful for calculating the size of beams of various shapes with the min size requirement of 230 mm x 230 mm.
How do you design a column?
The column can be designed using Excel sheets when required frequently throughout the project. One needs to only put values in an excel sheet once the excel sheet is made available. Complete details of the Designing column are given in this article.
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