2. Materials Required:
• MS Deformed Reinforcing Bars of
40/60 grade.
• Ordinary Portland Cement.
• Stone/Brick Chips (25 mm down
graded).
• Sylhet Sand (FM from 1.8 to 2.5).
• Coarse Sand (FM from 1.2 to 1.5).
2
4. Lap Lengths:
• Column 30 D
• Beam, Grade Beam, Slab35 D
(Where D is the Diameter of Rod)
4
5. Equipments:
• Concrete Mixture Machine
• Vibrator with Nozzles (One 1½”
diameter and the other 2” diameter)
• Batching Box
• Slum Cone
• Cube Mold
• Water pump
5
6. Items to be checked before
concreting:
A. Form Work
• Forms are cleaned and oiled.
• Horizontal and vertical level as well as
alignment.
• Spacing & size of planks and runner
(plank spacing maximum 7” c/c,
runner spacing 2’-0’ c/c)
6
7. • Peripheral forms are in same line and
level.
• Joints and leakages are properly
closed.
• Spacing of props is within 2’-0” to 2’-6”
c/c.
• Props are strong and properly tight.
7
8. B. Rebar
• Rebars are rust and straight.
• Size and spacing of rebars are as per
drawing.
• All crossing points are tightly fixed with
binding wire of 24 SWG.
• Extra tops are properly placed.
• Clear coverings and spacer blocks/
chairs are properly placed.
8
9. Mix proportions:
Mix proportions which are normally
mentioned in the drawing by the
consultant must be maintained strictly
(usually mixing ratios are 1:1½:3 and
1:2:4).
9
10. Admixture Mixing:
• If any leakage is found after casting of
UGWR and water meter pit then it will
be repaired by the grey cementitous
alloy.
• Before casting the same we have to mix
foam lub with cement – ½ Litre for 1
bag cement.
10
11. Construction Joints:
Construction joints in grade beam,
beam or slab will not be left at the
support. It will be left at minimum shear
point of grade beam, beam or slab. Bar
schedule will be prepared before
fabrication of reinforcement. No
casting of any structural member can
be done with aggregates mixed with
foreign materials. At the same time
casting will not be allowed in any place
which is water logged.
11
12. Curing for RCC Works:
1. RCC curing will be started after 24
hours of casting for normal condition.
2. If the weather is dry and hot, it may be
stared earlier.
3. The columns, walls and the footings
will be wrapped by the Hessian cloth.
12
13. 4. The Hessian cloth will always remain
in wet condition by sprinkling water.
5. Slab top will be ponded with water
until curing period is over.
6. RCC surface will be cured for at least
21 days after casting.
13
14. Materials Consumption :
For 100 cft of RCC works (1:1½: 3),
requirement is as follows:
• Cement 22 Bags
• Sylhet Sand 21 Cft
• Medium coarse sand 21 Cft
• Stone chips/brick chips 84 Cft
14
15. For 100 Cft of RCC works (1:2:4),
requirement is as follows:
• Cement 18 Bags
• Sylhet Sand 22 Cft
• Medium coarse sand 22 Cft
• Stone chips/brick chips 88 Cft
15
16. For 100 Cft of RCC works (1:6:6),
requirement is as follows:
• Cement 12 Bags
• Sylhet Sand 22 Cft
• Medium coarse sand 22 Cft
• Stone chips/brick chips 90 Cft
16
17. Test of construction materials:
Slump Test :
Slump Test is a test of concrete which
determines the water cement ration in
the field. The test is performed with
slump cone. The following figure is an
illustration of the Slump Test
17
18. Procedure of Slump Test :
1. Take a slump cone having top dia of
102 mm, bottom dia of 203 mm and
height of 305 mm. The base of 203 mm
dia is placed on a smooth surface.
Make the inner surface of the slump
cone clean and smooth.
2. Pour freshly prepared concrete into the
slump cone in three layers. Give at
least 25 blows for each layer with 4600
mm long and 16 mm dia plain rod.
During placing of concrete it should be
noticed that the cone is not disturbed.
18
19. 3. Remove the cone and measure the
difference in heights between the
central tip of subsided concrete and top
level of the cone which is the slump.
19
20. If the slump value is less than minimum,
then amount of water is to be
increased.
If the slump value is more than the
maximum, then the amount of water is
to be reduced.
Normally the water cement ratio (i. e.
w/e) is varied form 0.40 to 0.50 for RCC
slab, column etc. and above 0.60 for
pile casting.
20
21. Cube Test:
1. Mould Assembly:
a) Separate mould assembly and clean
all interior face, base with scraper to
remove rust / cement coating.
b) Assemble cube moulds checking every
dimension with 15cm long MS flat bar.
c) Oil the interior surface of the mould
with mold releasing oil to prevent
adhesion of concrete. Don’t use
excess oil. 21
22. 2. Sample Collection:
a) Sample should be the true
representative of concrete being used.
b) For site mixing, mixing time should be
at least one minute or 20 revolution of
the mixer from adding all aggregates
to obtain a homogeneous mix. For
ready mix concrete, before collecting
concrete it should be mixed properly
in the mixer truck.
22
23. c) Sample collecting pan should be
near, clean and free from any loose
material. Collecting pan may be slightly
moist with water but staking of water
should be avoided.
d) At least one set (3cubes) sample
should be taken from the same batch /
mix.
23
24. 3. Making Cubes:
a) Remix the sample thoroughly with
sampling scoop and trowel.
b) After remixing immediately fill the
mould in layers approximately 5 cm
deep (total 3 layers).
C) Each layer should be compacted with
the tamping each layer vibrate the
mould using rubber / wooden hammer
to remove air voids from concrete.
24
25. d) After Compacting the top layer, top
surface of the concrete shall be
finished level with the top of the mould,
using a trowel.
e) Store the cube moulds in a place
which is free from vibration and cover
the surface of the concrete with a piece
of damp sacking for initial 16 to 24
hours.
25
26. 4. Striping Moulds and Curing of
Cubes:
a) After 24 hours of casting cubes,
remove cubes from moulds. For ready
mix concrete some times it may take
more than 24 hours to harden the
concrete in that case wait until
concrete gains sufficient hardness.
26
27. b) After removing from mould mark
casting date and name of structure for
which concrete being used on the
cubes with a permanent marker.
Submerge cubes under clean water
for curing.
27
28. 5. Sending Cubes for Testing:
a) After 28 days take out cubes from
curing tank.
b) Send to laboratory / testing Authority
for test.
c) During transportation care should be
taken to avoid any damage (broken
edge) of cubes.
28
29. Expansion Joint has not done in Parapet at East Wall as per specification.
Picture as follows:
Expansion Joint has not done in Parapet at East Wall as per specification.
Picture as follows:
29
30. Expansion Joint hasn’t done in Parapet Wall at Roof Top [Length= 37 Rft (approx)]. Pictures as
follows:
Expansion Joint hasn’t done in Parapet Wall at Roof Top [Length= 37 Rft (approx)]. Pictures as
follows:
30
31. 1”to 1.5” width (Approx.) Kobla have physically done into the wall plaster surface into
the Bed room due to beam alignment has not done properly during beam casting
period. which is odd looking. But those Kobla haven’t mentioned into the drawing.
Pictures are as follows:
1”to 1.5” width (Approx.) Kobla have physically done into the wall plaster surface into
the Bed room due to beam alignment has not done properly during beam casting
period. which is odd looking. But those Kobla haven’t mentioned into the drawing.
Pictures are as follows:
31
32. High Window lintel Level & door lintel level hasn’t done same level of S.Bath. For this
reason Tiles top level & high window bottom level has not similar. Detail pictures are
as follows:
High Window lintel Level & door lintel level hasn’t done same level of S.Bath. For this
reason Tiles top level & high window bottom level has not similar. Detail pictures are
as follows:
32
33. Honey comb has found in slab and rod also visible. Details picture is as below:Honey comb has found in slab and rod also visible. Details picture is as below:
33
34. Stair beam casting work was not properly done in the electric pipe area. Details
picture is as below:
Stair beam casting work was not properly done in the electric pipe area. Details
picture is as below:
34
35. Stair beam casting is not done properly of electric pipe area. Details pictures are as below:Stair beam casting is not done properly of electric pipe area. Details pictures are as below:
35
36. Door side column cut for Door frame fitting which is beyond our policy. Details picture is as
below:
Door side column cut for Door frame fitting which is beyond our policy. Details picture is as
below:
36
37. Column has been cut for door clamp fitting. Details pictures are as below:Column has been cut for door clamp fitting. Details pictures are as below:
COLUMN RODCOLUMN RODCOLUMN RODCOLUMN ROD
37
40. Column have cut unfortunately for lintel casting. Even no extra rod has given before column
casting for lintel. Details pictures are as below:
Column have cut unfortunately for lintel casting. Even no extra rod has given before column
casting for lintel. Details pictures are as below:
40
41. Some improper casting of beam in the electric pipe area. Picture of honeycomb and casting area
are as below:
Some improper casting of beam in the electric pipe area. Picture of honeycomb and casting area
are as below:
41
42. Retaining wall casting out of alignment up to 3” to 4”. Detail picture is as follows:Retaining wall casting out of alignment up to 3” to 4”. Detail picture is as follows:
42
43. They didn’t keep MS Rod for veranda railing. Detail picture is as follows:They didn’t keep MS Rod for veranda railing. Detail picture is as follows:
43
44. COLUMN ROD HAS EXPOSED AT MACHINE ROOM TOP.COLUMN ROD HAS EXPOSED AT MACHINE ROOM TOP.
44
46. 16 mm Rod (8” Length) has found on Parapet Wall at Roof Top. Picture as follows:16 mm Rod (8” Length) has found on Parapet Wall at Roof Top. Picture as follows:
46
