Download - Ractangular+column
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Column designName of work:- pkn
1 External + self load 1200 kN Height of column 6.00 mtr
2 Concrete M- 25 Grade Unit weight concrete 25000
6 m 13.33
3 Steel fy 415 Tensile stress 190
4 Nominal cover 40 mm Effective cover 50 mm
5 Reinforcement Main vertical 20 6 Nos bars
6 2 - lgd. Strirrups 6 280 mm c/c
7 Rectangular Coloumn Size width 495 mtr depth 330 mtr
6 Nos. 20
495330
6280 m c/c
495
330
6.00
Ractangular column
Foundation pad
N/m3
cbc N/mm2
N/mm2 N/mm2
mm
mm
mm bars
mm 2 ldg strirrup
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Column design
1 External + self load 1200 kN/m Height of column 6.00 mtr = 60002 Concrete M 25 Unit weight concrete = ###
6 m = 13.333 Steel fy 415 Tensile stess = 1904 Nominal cover 40 mm Effective cover = 50 mm
1 Design Constants:- For HYSD Bars Cocrete M = 25
190 wt. of concrete = 25000 6
m 13.33m*c
=13.33 x 6
= 0.29613.33 x 6 + 190 1 - 0.296 / 3 = 0.901 0.5 x 6 x 0.90 x 0.296 = 0.8010
2 Design of section:-Minimum steel = 0.80% Let us use = 1 %steel 0.01Design column as a short columns
=p
=1200 x 1000
=152091
6 x( 1 - 0.01 )+ 0.01 x 190
Size of square column = ( 152091 = 390 mm Provide = 390 x 390Area of columns = 390 x 390 = 152100
3 Check column whatever short or long.= Height of column x Effective height factor
Here, = 6000 x 1 = 6000 mm b = 390 mm
Hence Hef = 6000 = 15.38 > 12 Design as long columnb 390
Reduction factore = Cr = 1.25 - Hef = 1.25 - 6000 0.9348 b 48 x 390= 1200 x 1000 = 1290323 N
0.93
=p
=1290323
=163539
6 x( 1 - 0.01 )+ 0.01 x 190Revised Ractangular column 1.50 x2= 163539 = 109026 x = 330 say 330
Size = 330 x 495 Area = 163350 (b = 1.5 d Assume)
N/m3cbc N/mm2
N/mm2 N/mm2
st = N/mm2 N/mm2cbc = N/mm3
k= m*c+stj=1-k/3
R=1/2xc x j x k
The load carring capacity of short column is p = cbc . Ac +st. Asc =cbc(Ag - pAs)+ st.pAs
From which Ag cbc (1-p) +p.st mm2
)0.5
mm2
Effective hieght of column Hef Hef
Revised Load P1The load carring capacity of short column is p = cbc . Ac +st. Asc = cbc(Ag - pAs)+ st.pAs
Revised Ag cbc (1-p) +p.st mm2
or x2
mm2
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4 Longitudinal Reinforcement:-0.01 x 163539 = 1635
using ### mm bars A = = 3.14 x 20 x 20 = 3144 x100 4 x 100Nomber of Bars = = 1635 / 314 = 5.21 say = 6 No.Hence Provided 6 bars of 20
having, Ast = 6 x 314 = 1884.00Keeping = 40 mm nominal side cover
5 Design of ties:-Diameter of ties should be 1/4 of the diameter of longitudinal reinforcement subject to
minimum 6 mm. However use 6 The spacing of the ties should not exceed least of the following.
(I) Least lateral diamension. = 390 mm(II) 16 x Diameter of main bars 16 x 20 = 320 mm(III) 48 x dia of ties 48 x 6 = 288 mm
Hence provided the ties @ = 280 mm c/c. The ties will be square in shape in two size as shown in fig. using them alternately, so that longitudinal bars pass through the corners of ties.
Keep pitch of each set of ties at = 280 mm
Asc =pA = mm2
3.14xdia2
Ast/Amm bar,
mm2
mm bars of ties.
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Column design
mm
152091
mm
163539
mmAssume)
mm2
mm2
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Diameter of ties should be 1/4 of the diameter of longitudinal reinforcement subject to
The ties will be square in shape in two size as shown in fig. using them alternately, so that longitudinal bars pass through the corners of ties.
mm2
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Column designName of work:- pkn
495
206 Nos bars
330
40mm cover
Square column
330
495
6.00 mtr
Foundation pad
mm
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Length effect coefficient
Height lef = 0.80L lef = 1.00L lef = 1.2L lef =1.5L lef = 2L lef =2L
case 1 case 2 case 3 case 4 case 5 case 6 case 7.
case no. Degree of end restraint of compression member1 Effectively held in position and restrained against rotation at both ends
2 Effectively held in position at both ends, restrained regainst rotation atone ends.
3 Effectivly held in position at both ends, buy notrestrained regainst rotation .
4 Effectively held in position, restrained regainst rotation atone ends. And at the other restrained against rotation but not held in position
5 Effectively held in position, restrained regainst rotation atone ends. And at the other partialy restrained against rotation but not held in position
6 Effectively held in position, at one ends but not restrained against rotation,. And at the other end restrained against rotation but not held in position
7 Effectively held in position, and restrained against rotation at one endbut not held in position nor restrained against rotation at the other end.
lef = 0.65L
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VALUES OF DESIGN CONSTANTSGrade of concrete M-15 M-20 M-25 M-30 M-35 M-40 Grade of concrete
Modular Ratio 18.67 13.33 10.98 9.33 8.11 7.185 7 8.5 10 11.5 13
93.33 93.33 93.33 93.33 93.33 93.330.4 0.4 0.4 0.4 0.4 0.4
Development Length in tension0.867 0.867 0.867 0.867 0.867 0.8670.867 1.214 1.474 1.734 1.994 2.2540.714 1 1.214 1.429 1.643 1.8570.329 0.329 0.329 0.329 0.329 0.329 M 150.89 0.89 0.89 0.89 0.89 0.89 M 20
0.732 1.025 1.244 1.464 1.684 1.903 M 250.433 0.606 0.736 0.866 0.997 1.127 M 300.289 0.289 0.289 0.289 0.289 0.289 M 350.904 0.904 0.904 0.904 0.904 0.904 M 400.653 0.914 1.11 1.306 1.502 1.698 M 450.314 0.44 0.534 0.628 0.722 0.816 M 500.253 0.253 0.253 0.253 0.253 0.2530.916 0.916 0.916 0.914 0.916 0.9160.579 0.811 0.985 1.159 1.332 1.5060.23 0.322 0.391 0.46 0.53 0.599
bd M-15 M-20 M-25 M-30 M-35 M-400.18 0.18 0.19 0.2 0.2 0.2
0.25 0.22 0.22 0.23 0.23 0.23 0.230.50 0.29 0.30 0.31 0.31 0.31 0.32 M 100.75 0.34 0.35 0.36 0.37 0.37 0.38 M 151.00 0.37 0.39 0.40 0.41 0.42 0.42 M 201.25 0.40 0.42 0.44 0.45 0.45 0.46 M 251.50 0.42 0.45 0.46 0.48 0.49 0.49 M 301.75 0.44 0.47 0.49 0.50 0.52 0.52 M 352.00 0.44 0.49 0.51 0.53 0.54 0.55 M 402.25 0.44 0.51 0.53 0.55 0.56 0.57 M 452.50 0.44 0.51 0.55 0.57 0.58 0.60 M 502.75 0.44 0.51 0.56 0.58 0.60 0.62
3.00 and above 0.44 0.51 0.57 0.6 0.62 0.63
Grade of concrete M-15 M-20 M-25 M-30 M-35 M-401.6 1.8 1.9 2.2 2.3 2.5
bd (N / mm2
cbc N/mm2
m cbc
(a) st = 140
N/mm2 (Fe 250)
kcjcRc Grade of
concretePc (%)
(b) st = 190
N/mm2
kcjcRc
Pc (%)
(c ) st = 230
N/mm2 (Fe 415)
kcjcRc
Pc (%)
(d) st = 275
N/mm2 (Fe 500)
kcjcRc
Pc (%)
Permissible shear stress Table v in concrete (IS : 456-2000)100A s Permissible shear stress in concrete tv N/mm2
Grade of concrete< 0.15
Maximum shear stress c.max in concrete (IS : 456-2000)
c.max
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Reiforcement %
M-20 M-20bd bd
0.15 0.18 0.18 0.150.16 0.18 0.19 0.180.17 0.18 0.2 0.210.18 0.19 0.21 0.240.19 0.19 0.22 0.270.2 0.19 0.23 0.30.21 0.2 0.24 0.320.22 0.2 0.25 0.350.23 0.2 0.26 0.380.24 0.21 0.27 0.410.25 0.21 0.28 0.440.26 0.21 0.29 0.470.27 0.22 0.30 0.50.28 0.22 0.31 0.550.29 0.22 0.32 0.60.3 0.23 0.33 0.650.31 0.23 0.34 0.70.32 0.24 0.35 0.750.33 0.24 0.36 0.820.34 0.24 0.37 0.880.35 0.25 0.38 0.940.36 0.25 0.39 1.000.37 0.25 0.4 1.080.38 0.26 0.41 1.160.39 0.26 0.42 1.250.4 0.26 0.43 1.330.41 0.27 0.44 1.410.42 0.27 0.45 1.500.43 0.27 0.46 1.630.44 0.28 0.46 1.640.45 0.28 0.47 1.750.46 0.28 0.48 1.880.47 0.29 0.49 2.000.48 0.29 0.50 2.130.49 0.29 0.51 2.250.5 0.300.51 0.300.52 0.300.53 0.300.54 0.300.55 0.310.56 0.310.57 0.310.58 0.310.59 0.31
Shear stress tc100A s 100A s
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0.6 0.320.61 0.320.62 0.320.63 0.320.64 0.320.65 0.330.66 0.330.67 0.330.68 0.330.69 0.330.7 0.340.71 0.340.72 0.340.73 0.340.74 0.340.75 0.350.76 0.350.77 0.350.78 0.350.79 0.350.8 0.350.81 0.350.82 0.360.83 0.360.84 0.360.85 0.360.86 0.360.87 0.360.88 0.370.89 0.370.9 0.370.91 0.370.92 0.370.93 0.370.94 0.380.95 0.380.96 0.380.97 0.380.98 0.380.99 0.381.00 0.391.01 0.391.02 0.391.03 0.391.04 0.391.05 0.391.06 0.391.07 0.391.08 0.41.09 0.41.10 0.4
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1.11 0.41.12 0.41.13 0.41.14 0.41.15 0.41.16 0.411.17 0.411.18 0.411.19 0.411.20 0.411.21 0.411.22 0.411.23 0.411.24 0.411.25 0.421.26 0.421.27 0.421.28 0.421.29 0.421.30 0.421.31 0.421.32 0.421.33 0.431.34 0.431.35 0.431.36 0.431.37 0.431.38 0.431.39 0.431.40 0.431.41 0.441.42 0.441.43 0.441.44 0.441.45 0.441.46 0.441.47 0.441.48 0.441.49 0.441.50 0.451.51 0.451.52 0.451.53 0.451.54 0.451.55 0.451.56 0.451.57 0.451.58 0.451.59 0.451.60 0.451.61 0.45
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1.62 0.451.63 0.461.64 0.461.65 0.461.66 0.461.67 0.461.68 0.461.69 0.461.70 0.461.71 0.461.72 0.461.73 0.461.74 0.461.75 0.471.76 0.471.77 0.471.78 0.471.79 0.471.80 0.471.81 0.471.82 0.471.83 0.471.84 0.471.85 0.471.86 0.471.87 0.471.88 0.481.89 0.481.90 0.481.91 0.481.92 0.481.93 0.481.94 0.481.95 0.481.96 0.481.97 0.481.98 0.481.99 0.482.00 0.492.01 0.492.02 0.492.03 0.492.04 0.492.05 0.492.06 0.492.07 0.492.08 0.492.09 0.492.10 0.492.11 0.492.12 0.49
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2.13 0.502.14 0.502.15 0.502.16 0.502.17 0.502.18 0.502.19 0.502.20 0.502.21 0.502.22 0.502.23 0.502.24 0.502.25 0.512.26 0.512.27 0.512.28 0.512.29 0.512.30 0.512.31 0.512.32 0.512.33 0.512.34 0.512.35 0.512.36 0.512.37 0.512.38 0.512.39 0.512.40 0.512.41 0.512.42 0.512.43 0.512.44 0.512.45 0.512.46 0.512.47 0.512.48 0.512.49 0.512.50 0.512.51 0.512.52 0.512.53 0.512.54 0.512.55 0.512.56 0.512.57 0.512.58 0.512.59 0.512.60 0.512.61 0.512.62 0.512.63 0.51
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2.64 0.512.65 0.512.66 0.512.67 0.512.68 0.512.69 0.512.70 0.512.71 0.512.72 0.512.73 0.512.74 0.512.75 0.512.76 0.512.77 0.512.78 0.512.79 0.512.80 0.512.81 0.512.82 0.512.83 0.512.84 0.512.85 0.512.86 0.512.87 0.512.88 0.512.89 0.512.90 0.512.91 0.512.92 0.512.93 0.512.94 0.512.95 0.512.96 0.512.97 0.512.98 0.512.99 0.513.00 0.513.01 0.513.02 0.513.03 0.513.04 0.513.05 0.513.06 0.513.07 0.513.08 0.513.09 0.513.10 0.513.11 0.513.12 0.513.13 0.513.14 0.51
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3.15 0.51
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M-10 M-15 M-20 M-25 M-30 M-35 M-40 M-45 M-50-- 0.6 0.8 0.9 1 1.1 1.2 1.3 1.4
Development Length in tension
Plain M.S. Bars H.Y.S.D. Bars
0.6 58 0.96 600.8 44 1.28 450.9 39 1.44 401 35 1.6 36
1.1 32 1.76 331.2 29 1.92 30
Mod
ifica
tion
fact
ore
2.01.3 27 2.08 281.4 25 2.24 26
1.4
1.2
0.8
0.4
0.0(N/mm2) (N/mm2) (N/mm2)
3.0 300 2.5 250 -- --5.0 500 4.0 400 0.6 607.0 700 5.0 500 0.8 808.5 850 6.0 600 0.9 9010.0 1000 8.0 800 1.0 10011.5 1150 9.0 900 1.1 11013.0 1300 10.0 1000 1.2 12014.5 1450 11.0 1100 1.3 13016.0 1600 12.0 1200 1.4 140
Permissible Bond stress Table bd in concrete (IS : 456-2000)
bd (N / mm2) kd = Ld bd (N / mm2) kd = Ld
Permissible stress in concrete (IS : 456-2000)Permission stress in compression (N/mm2) Permissible stress in bond (Average) for
plain bars in tention (N/mm2)Bending cbc Direct (cc)Kg/m2 Kg/m2 in kg/m2
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0.4 0.8 1.2 1.6 2Percentage of tension reinforcement
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2 2.4 2.8
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DATA sheetDesignDrawingEffective lenght cofficientIS_Table