4.10.2 Fixing of reinforcement
The steel reinforcement shall be assembled
to
the
exact
shapes
and
dimensions as approved by the Engineer.
The
rods
shall
have
the
approved cross-sectional area and shall be fixed accurately in the moulds. The ends of all tying wires
shall be turned into the main body of the
concrete and shall not be allowed to project towards the surface. Spacing blocks shall be used to ensure accurate cover to the reinforcement, where necessary, and these blocks
shall be of precast concrete
of a strength at least equal to that of the concrete being placed. They shall be as small as
possible in view of practicality and shall be securely fixed in position
by means of wires to be cast into them.
No temporary
supports
for
the
reinforcement
shall
be
allowed
to
be
incorporated into the finished concrete. At the
time
of
concreting
all
reinforcement shall have been thoroughly cleaned and made free
of all loss rust (crude oil or any other coatings that might destroy or reduce
the bond).
Unless otherwise specified or shown on the drawings, minimum cover shall be determined in accordance
with
ACI 318- 77 as indicated on the
following table:
Description
|
Min. cover thickness
|
||
Cast against and permanently exposed to earth
|
75
mm
|
||
Exposed to earth and weather
|
D16
and smaller
|
40
mm
|
|
D19
- D 25
|
50
mm
|
||
Not Exposed to weather and
|
Slabs and walls
|
D25
and smaller
|
20
mm
|
not in
contact
with earth
|
Beams, girder, columns
|
main bars , ties, stirrups
|
40
mm
|
