Why Clear cover is important?
1. Corrosion prevention &
environmental protection of Rebar
2. Gaining proper strength of
concrete without sleep
3. Provide insulation from fire or
heat
Is more clear cover always good?
No.
More clear cover may lead to crack. If crack width exceeds the allowable limit
which is provided by design code, then moisture may occur corrosion of
reinforcement & deterioration of concrete may occur.
Table 1.2.1:
Clear Cover in Different codes
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|
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ACI 318-99
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BS 8110
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IS 456-2000
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EURO
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BEAM
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|||||
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FB
|
1.5 inch
|
1 inch
(25 mm)
|
1 inch
(25 mm)
|
1 inch
(25-30 mm)
|
|
|
GB
|
1.5 inch
|
1 inch
(25 mm)
|
1 inch
(25 mm)
|
1 inch
(25-30 mm)
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|
|
Foundation Beam
|
2.5 inch
|
1 inch
(25 mm)
|
2 inch
(50 mm)
|
2 inch
(40-50 mm)
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COLUMN
|
|||||
|
|
ABOVE GB
|
1.5 inch
|
1 inch
(25 mm)
|
1.5 inch
(40 mm)
|
1 inch
(25-30 mm)
|
|
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BELOW GB
|
2.5 inch
|
1 inch
(25 mm)
|
1.5 inch
(40 mm)
|
1 inch
(25-30 mm)
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SLAB
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|||||
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Normal Slab
|
0.75 inch
|
0.8 inch
(20 mm)
|
0.8 inch
(20 mm)
|
20-25 mm
|
|
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Flat Slab
|
|
|
25 mm
|
25-30 mm
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FOOTING
|
|||||
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Bottom
|
3-4 inch
|
2 inch
(50 mm)
|
2 inch
(50 mm)
|
50-75 mm
|
|
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Side
|
2.5-3 inch
|
|
|
|
|
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Raft Footing bottom
|
|
50 mm
|
75 mm
|
|
|
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Raft Footing Top
|
|
|
50 mm
|
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