Reinfocing details of column

REINFORCING
DETAILS OF RCC
COLUMN &FOOTING

Column
• Columns are vertical compression members
of a structural frame intended to support the
load-carrying beams. They transmit loads
from the upper floors to the lower levels
and then to the soil through the foundations.
• Usually columns carry bending moment as
well, about one or both axes of the cross
section, and the bending action may
produce tensile forces over a part of the
cross section
• Reinforcement are provided in order to
reduce the size of the column

• The main reinforcement in columns is
longitudinal, parallel to the direction of the load
and consists of bars arranged in a square,
rectangular, or circular shape

• Main steel is provided to resist compression load
along with concrete
• Reinforcement Requirements (Longitudinal Steel
Ast)
min Ast 0.8 % of C/S
max Ast 6% of C/S

• The object of stipulating a min. percentage of
steel is to make provision to prevent buckling of
column due to any accidental eccentricity of the
load on it
• For stipulating a max. percentage of steel is to
provide reinforcement with in such a limit to
avoid congestion of reinforcement which would
make it very difficult to place the concrete and
consolidate it

• Min. 4 bars in rectangular/square column and min. 6
bars in circular shape column
• The bar shall not be less than 12mm
• The nominal cover shall any case not be less than
40mm.
• In our site they provided 40mm cover
• Min. distance b/w individual bars
-the dia of larger bar
-5mm more nominal max. size of coarse aggregate

• Spacing of longitudinal bars shall not exceed
300mm from the periphery of the column
• in our site they provided rectangular and circular
columns
• For rectangular column
• -distributed the reinforcement equally on four
sides

• - the no. of bars in a column are varying from 10,
12,14, 16, of varying diameter
• They provide different diameter main bars i.e.,
16mm,20mm,25mm
• In our site 450mm dia. circular column Is used
• For circular column they provide 6 nos 20mm
dia. And 6 nos 16mm dia
• The effective length provide is 48 times the dia .
Of bar

TRANSVERSE REINFORCEMENT
• In order to maintain the position of longitudinal
reinforcement and also to prevent their buckling
which may cause splitting of concrete. It is also assist
confining the concrete
• The diameter of transverse reinforcement shall not be
less than 1/4th dia. of main bar in no case less than
5mm
• The spacing of lateral ties
the least lateral dimension of the column/16times the
dia. Of main bars
max spacing is 300mm

• In our site they provided lateral ties of diameter
8mm at a spacing 200 and 250mm c/c

Reinfocing details of column

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to Reinfocing details of column

Similar to Reinfocing details of column (20)

Recently uploaded

Recently uploaded (20)

Reinfocing details of column