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 -1Session : 2015-2016

Student ID:141065 141070141066 141071141067 141072141068 141073141069 141074

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

Objectives To know the arrangement of RCC Column.

To know about design specification.

To know about the characteristic of Column

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.

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 .

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

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.

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.

Clear Distance between Reinforcing BarsACI 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 CoverClear concrete cover is not to be taken less than 4 cm for columns

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.

Tie and spiral arrangements

Spirals Not less than 10 mm in diameter. Less than 2.5 cm and not more than 7.5 cm Bundled BarsGroups of parallel reinforcing bars

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.

Details of HOOKS

• Standard length of hook 6d or 75mm

• Bending angle must be 135 ͦ

Thank you being with

us.