2. Content
1. Introduction
2. Centre line plan
3. Foundation of Structure
4. Preparation prior casting of slab
5. Equipment
6. Volume of concrete
7. Activities carried out after casting of slab
8. Conclusion
9. References
3. 1.Introduction
• It is a residential building having a proposal of 7-2bhk flat.
• Site location:- Goddhni, Nagpur
• Plot area:-3600sft
• Plinth area:-1100sft
• Slab area:-1559sft
• Number of flats:-7 flats
• Builder name:- Kishore Dhawas
• Name of firm:-City developers, Nagpur
• Architect: - Samir Deshmukh
• Structural designer: - Prasanna Kulkarni
• Site engineer: - Ajay D. Shahu
• Work duration:-7june to 7july
5. 3.Foundation of the Structure
A. Single Spread Slope Footing
• The base of the column is enlarged or spread to provide individual
support for the load.
• A spread slope footing is a type or shallow foundation used to transmit
the load of an isolated column to the subsoil.
• Numbers of footing provided=19 no.
• Size of footing
F1= (1500×1600),
F2= (1500×1400)
6. B. Sectional detail
F1= (1500×1600), F2= (1500×1400)
F1= (1500×1600),
•It is a cress section of footing, showing
the reinforcement at the bottom of footing
and in the column.
8. 4. PREPARATION PRIOR TO CASTING OF SLAB:-
A. Level fixing
To maintain the slab at same an accurate level, i.e.
all the four corners of inner face the slab are must
be at same height from the floor level. Thus, to
maintain the slab at same height, levelling is
carried out by using
level pipe,
thread and
Tape.
9. B. Formwork: - The formwork is built on site out of
timber, plywood and particleboard.
Use and application of centring can be made in
following manner:-
Fixing Column caps
Fixing beam bottom(wooden plank having width of
beam)
Providing support-Lumbers or props to rafters or
span
Laying steel plates or plywood for slab
10. Column caps, beam bottoms
With beam sides and proving
Support.
Laying steel plates over
Rafter or span
11. C. Checking of mould formed by formwork
After completing all shuttering work, the next step is to check that
the available dimension over formwork (dimension of mould) is
same as required for beam, column, duct and slab.
Checking the length, width and depth of beam, slab area over each
room is same as specified dimension.
If any dimension of mould is found incorrect, then it is corrected at
the same time.
12. D. Line and Levelling:-
Levelling is done in order to obtain flat and horizontal slab.
13. E. Oiling surface of formwork
A thin single layer of burned engine oil is applied
manually over the surface of formwork. Advantage:-
a. To prevent the corrosion.
b. To prevent the absorption of slurry.
c. To fill the fine gaps, voids and various joints.
d. To prevent the spilling of concrete slurry.
e. To loosen the bond between roofing material of
formwork and the roof of slab, thus removing the
formwork easily.
f. To increase the life of both steel, wood and ply
formwork .
14. F. Reinforcement cutting and binding
The diameter, length and number of the bar required can be
obtained from the structural drawing and bar bending schedule of
the slab.
Cutting
Bending
Centre-to- centre distance is marked over formwork surface
This marking referred as the point to lay longitudinal and transverse
bars.
In case of beams, the centre-to-centre distance between two ties is
marked on the longitudinal bars of that beam.
Then the ties are placed and tied with binding wire at that point.
After bar-binding work is over, engineer checks the reinforcement of
the slab before casting and thus get corrected.
16. G. Providing Cover: -
Cover is the distance between the centre of the road and the
periphery of the structural member. Minimum cover for slab is
15mm.
17. H. Working out the quantity of concrete: -
By referring structural drawing, total quantity of concrete can worked
out.
Advantages of working out the quantity are as under:-
a. To know the volume of coarse aggregate, fine aggregate, number of
cement bags requires.
b. To know the nearest variation in the volume of concrete which may
occur during casting due to few irregularities, such as
c. Adding Less aggregate during batching
d. Unequal depth of slab
To prevent wastage of concrete
To know the nearest expenditure required to cast the slab
To employ the contractor to cast slab
In piece work basis or
On rate basis.
18. Since concrete of grade M20 is used for casting slab, the ratio is
1:1.5:3.
This prepared concrete is discharged in a pan of tower hoist, thus
concrete is transported vertically up to the second floor from ground
floor and then it is discharge.
Manual transportation of material.
Vibration-needle vibrator.
If depth of slab is maintained.
Finishing.
Curing of concrete by ponding for minimum 15 days.
I. Casting of slab
20. 5. Equipment:-Major equipment required during and before
casting of slab are as under:-
Cubical gauge box
(Farma):- Volume of gauge
box is 0.035m3
. It is use to
volume batching of fine
aggregate and coarse aggregate
Bar bending keys-use to
bend bars.
21. Transit mixture-use to make
concrete by thoroughly mixing
sand, aggregate, cement and
water in proportionate amount
Vertical hoist-use to lift the
concrete vertically from ground
floor to higher floors.
Niddle vibrator-use to
penetrate into deep beam and
results in better compaction.
Hook-use to bind
reinforcement with binding
wire.
22. 6. WORKING OUT THE VOLUME OF CONCRETE: - Volume of concrete calculated by
using structural drawing, floor plan and bar bend schedule of slab, beam and column.
Total volume of concrete
Thus the total volume of concrete required for slab is 25.956m3
.
Therefore, adding 52% to get dry volume=1.52×25.956=39.453m3
.
For M20 grade, volume of cement is=39.453/ (1+1.5+3) =7.173m3.
Therefore, no. of .cement bags=7.173÷.034=205bags
Volume of fine aggregate=7.173×1.5=10.759m3
.
Volume of coarse aggregate=7.173×3=21.519m3
total volume
SR.NO. MEMBERS VOLUME UNIT
1 BEAMS-R 4.9868 CUB.MT.
2 BEAMS-H 8.6064 CUB.MT.
3 SLAB 9.2566 CUB.MT.
4 BALCONY 1.1878 CUB.MT.
5 COLUMN 1.9184 CUB.MT.
TOTAL 25.956 CUB.MT.
total volume
SR.NO. MEMBERS VOLUME UNIT
1 BEAMS-R 4.9868 CUB.MT.
2 BEAMS-H 8.6064 CUB.MT.
3 SLAB 9.2566 CUB.MT.
4 BALCONY 1.1878 CUB.MT.
5 COLUMN 1.9184 CUB.MT.
TOTAL 25.956 CUB.MT.
23. 7. Activities to be carried out after casting of slab:-
A. Removing some part of formwork or centring:-
16-24 hours is the minimum period before striking vertical
formwork of columns, walls and beams.
B. Inspection: -
A simple inspection is carried out to see the quality of concreting
and appearance of finishing surface when formwork is removed. If
any defect is detected such as :-
Honey combing,
Rough surface due to segregation of concrete, etc. appear on the
surface on beam sides after hardening
then it is repaired by applying
Cement paste on that surface or
Grouting.
24.
25. C. Marking of centreline
It is done by taking the reference of column position at plinth level
and transferring the point on the surface of slab at all four corners, so
that position of column above the slab must be located exactly over
the column below the slab.
The centre-to-centre distance between upcoming columns over slab
must be marked as per centre line drawing.
Using centre line marking, dimension of column (B×D) can be
located.
Diagonal check can also be obtained and can also be corrected, if
found incorrect.
26. D. Ponding and Curing
small ponds of rectangular shape prepared on the
hardened surface of slab throughout the surface
area by using mortar prepared in a ratio of 1:8 to
1:10.
This rectangular pond after hardening is filled with
water, thus curing the concrete.
This poor quality of mortar is so prepared so that it
can be easily removed from the slab surface after
curing.
27. E. Casting the starter before casting of column:-
Starters are the portion of column of depth 75-100mm
approximately.
Wooden mould is of the size of column which is used to cast the
starter and is placed over the located position of column by referring
centreline.
Then the mould is filled with concrete of grade M20.
After hardening concrete, mould is removed……………contd.
28. 8. Conclusion
Industrial training has helped to understand the theoretical concepts
of the various subjects such as
Foundation Engineering,
Estimation and Costing,
Concrete Technology,
Building Construction and their relation with practical means.
It has also helped me to understand the managerial part of planning
with respect to proper and timely execution of work, material
management, etc. Industrial training develops a skill of observation,
and a skill to understand the various problems faced at site and the
way to overcome with this problems.
Since my training report in on the residential building, it has given
me the opportunity to calculate the volume of concerte required to
cast the slab which is a sure means of practical knowledge. It has also
given me the idea about the importance of stepwise execution of
work.
