RCC Column Shuttering Design

 RCC Column Shuttering Design

Formwork : the process of creating a temporary mold into which concrete is poured and formed.

Traditional formwork is fabricated using timber, formwork should be enough strong to withstand the pressure of concrete

watch full on youtube Column Shuttering Design

Materials required for Shuttering

1. 12mm wooden ply
2. walling patti ( 4" x 1")
3. Waler ISMC 100x50
4. Tie Rod 16mm
5.  Nails

                                                                            Fig. Shuttering of Column

 

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