Column Details

1. Detailing of Reinforced Concrete Column
Course No : CE-2106
Course Title : Design of Concrete Structures -1 Sessional
Submitted to:
 Prof. Dr. Md. Mozammel Hoque
Professor
Md . Suman Mia
Lecturer
Department of Civil Engineering
DUET,Gazipur
Submitted by :
Group No: B1 -1
Session : 2015-2016
Student ID:
141065 141070
141066 141071
141067 141072
141068 141073
141069 141074

2. Content
 Objectives
 Column relevant definition
 Classification of column
 Minimum number of reinforcement bar
 Design consideration
 Clear distance between RC bar
 Ties
 Tie and spiral arrangement
 Spiral and bundle bar
 Lapping of Main bar
 Details of Hooks

3. Objectives
 To know the arrangement of RCC Column.
 To know about design specification.
 To know about the characteristic of Column

4. Column relevant definition
 Column:
o Basically compression member
for which axial force is substantial
amount.
o Columns support axial loads from
the roof slabs and transfer these
loads to the footings.

5. Column relevant term
 Main bar: Which basically carry the
axial load.
 Tie: Holds the main bar as well as
core concrete.
 Spacing: Centre to centre distance
between tie bar.
 Clear covering : The space between
outer face of column to tie bar which
protect the bar from weather effect .

6. Types of Column
 Columns are divided into three types according to the way they are
reinforced.
1. Tied Columns
2. Spirally-Reinforced Columns
3. Composite Columns

7. Minimum Number of Reinforcing Bars
 ACI Code 10.9.2 specifies :
For Tied Column:
Minimum of four bars within rectangular or
circular sections; or one bar in each corner of the cross
section for other shapes.
For Spiral Column:
Minimum of six bars in spirally reinforced
columns.

8. Design Consideration
 ACI Code 10.9.1 specifies tie ratio :
Minimum reinforcement ratio of 1 % and maximum 8 % is to be used in tied
or spirally reinforced columns.
 BNBC specifies tie ratio :
 Minimum reinforcement ratio of 1 % and maximum 6 % is to be used in tied
or spirally reinforced columns.

9.  Clear Distance between Reinforcing Bars
 ACI Code 7.6.3 and 7.6.4 specify :
For tied or spirally reinforced
columns, clear distance between bars is not to be less than the
larger of 1.50 times bar diameter or 4 cm.
 Concrete Protection Cover
Clear concrete cover is not to be taken less than 4
cm for columns

10. Ties
 For longitudinal bars 32 mm or smaller.
 Lateral ties 10 mm in diameter.
ACI Code 7.10.5.2 specifies :
Vertical spacing of ties is not to exceed the smallest of:
 16 times longitudinal bar diameter.
 48 times tie diameter.
 Least cross sectional dimension.

11. Tie and spiral arrangements

13. Spirals
 Not less than 10 mm in diameter.
 Less than 2.5 cm and not more than 7.5 cm
 Bundled Bars
 Groups of parallel reinforcing bars

14. Lapping of Main bar
No lap should be allowable at
the joint of beam and column.
Lapping should not be
allowable at same level
Lapping must be provide at
middle position of the column.

15. Details of HOOKS
• Standard length of hook 6d or
75mm
• Bending angle must be 135 ͦ

16. Thank you
being with us.