RCC column Shuttering Design (2400mm pour height)

 Design of RCC column shuttering

Assumptions & Constants:

 

Concrete Density: 2500 Kg /m3

 

Steel Properties:

E, Modulus of Elasticity = 200000 Kg/cm2

Allowable Shear Stress = 1000 kg/cm2

 

Wood Properties:

E, Modulus of Elasticity = 70000 kg / cm2

Allowable Shear Stress = 7 kg/cm2

 

Load Calculation:

RCC Column Pour Depth (Height of Column) = 2400 mm

Dead Load of Slab = 2.40 m x 2500 Kg /m3 = 6000 Kg/m2

 

Maximum Area Load on Wall / Column Shuttering Material

Per Sq. m = 6000 Kg /m2

 

 

DESIGN WORKING:

 

1 .Design for Plywood 12 mm

 

Consider 12 mm Plywood, 1 cm Strip wide, supported @ 200 mm c/c by

Wooden Patti (4” x 1’’)

Load on Plywood = 6000 kg/ Sq. m

UDL on 1 cm Strip Plywood = 0.60 Kg / cm

1 cm strip

Analysing as a Simply Supported Beam

 

 

 

DEFLECTION CHECK:

Ixx = 0.144 cm4 (derived)

Actual Deflection = (5 / 384)* (WL4 / E I) = (5/384)*(0.6*20)⁴ /(200000*0.144)= 0.043 cm

Allowable Deflection = L / 360 = 20 / 360 = 0.056 cm

0.043<0.056 i.e.

 SAFE

SHEAR CHECK:

Shear Stress of rectangular section = 1.5 x V (shear force) / Area

 

=1.5 x V (shear force) / (b x d)

= 1.5 x 3 kgs / (1 x 1.2) . . . . 1.2 cm depth

= 3.75 Kg /cm2 < Allowable 7 kg /cm2 (as per IS 883)

SAFE

 

PLYWOOD USED SHALL BE 12 mm AND SHALL BE SUPPORTED @ 200 MM c/c

By Patti 4’’ x 1’’

 

2. Design of Wooden Patti ( 4’’ (b) x 1’’( d))

Providing Wooden Patti (4’’(b) x 1’’ (d) )

I xx = 13.87 cm4

Span of Patti = 200 mm

c / c of Patti = 200 mm

UD Loading on Patti = 6000 kg/Sq. m X 0.2 m = 1200 Kg /m

Reaction of Patti = 1200 kg/m x 0.2 m x 0.5 (half) = 120 Kgs.=wl/2

 

Design of Wooden Patti: (as a Simply Supported Member, Supports @ 200 mm)

DEFLECTION CHECK:

Check for Deflection = (5 / 384) * (WL⁴ / E I)

Actual Deflection = 0.018 cm

Allowable Deflection (L / 360) = 20 / 360 = 0.056 mm

0.018cm < 0.056cm

SAFE

 

SHEAR CHECK:

Shear Stress = 1.5 x V (shear force) / (b x d)

= 1.5 x 120 kgs / (10.16 cm x 2.54 cm)……..1’’=2.54cm,4’’x1’’

= 6.98 Kg /cm2 < Allowable 7 kg /cm2 (as per IS 883)

 

SAFE

 

Wooden Patti USED SHALL BE 4” (b) X 1” (d), PLACED @ 200 mm c/c , supporting Plywood.

 

3. Design Working for Waler Member, supporting Wooden Patti.

 

Providing …… back to back … C Channel 100x 50 mm ….. ] [

PROPRETIES

I xx = 350 cm4

Span of Waler = 2500 mm (tie rods through ply OR Tie rods at end of Column)

C / c of Waler = 200 mm

Loading (Point Loads from Wooden Patti @ 200 mm c/c / Reaction of Wooden Patti) = 120 Kgs.

Reaction of Waler Member = 120 x 14 X 0.5 (half) = 840 Kgs (tensile force on Tie Rod)……….2500/200=14 point loads

 

Design of Waler Member:

 (As a Simply Supported Member, Supports @ 2500 mm)

The Waler Member shall be subjected to maximum 14 Point loads of 120 Kgs Each.

Analysing:

 

DEFLECTION CHECK:

Check as Simply Supported, with Multiple Point Loads (120 Kgs) (acting simultaneously)

Actual Deflection = (a2 * b2 * W) / (3 * E * I * L)

= 0.372 cm

Allowable Deflection (L / 325) = 0.769 cm

0.372<0.769

SAFE

 

 

SHEAR CHECK:

 

Shear Stress = V (shear force) / (b x d)

= 840 kgs / (0.4 cm x 10 cm)

= 210 Kg /cm2 < Allowable 1000 kg /cm2 (as per IS 800)

SAFE

 

PROVIDE back/back C Channel 100 x 50 mm (8.66kg/m each) , AS Waler Member for Column.

4. Design Tie Rod (16 mm Diameter)

Provide 16 mm Tie Rod.

Properties:

Diameter: 16 mm

Area of circle= (3.14/4)*(d²) = 2.01 cm2

For Steel (HYSD 250) Allowable Tensile Stress: 1200 Kg / m2

Actual Tensile Force on Each Tie Rod as derived earlier = 840 Kgs

Allowable Tensile Force = (Allowable tensile stress) x (cross sec. Area)

= 1200 x 2.01

= 2412 kgs > actual: 840 kgs

SAFE

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