A Brief Account of my Inplant Training done at Road Construction Division, Giridih.

2. Length Of Road= 79 km
No. Of Culverts = 44
No. Of Bridges = 2
Widening and
Strengthening of Kowar
Kodarma Road
• The Road Passes through
many thickly populated
villages.
• Width of the existing crust
is 3 m.
• Which is to be widened up
to 7 m.
• The improvement of this
road will uplift the social and
economic condition of the
area.

3. The materials used in
the above layers has to
go through various
quality control checks
•Granular Sub Base (GSB)
•Wet Mix Macadam (WMM)
•Bituminous macadam (BM)
•Semi dense bituminous concrete (SDBC)

4. Water Absorption test
Aggregate Impact test
Flakiness Index
Sieve analysis
Bitumen content test

5. A traffic census had been conducted previously at three points on the
road continuously for 7 days to get average daily traffic. Number of CV/day
is obtained from it, denoted by ‘P’
Cumulative Traffic is
found out as given in IRC
37 -2001.
From the Cumulative
Traffic, and known CBR
value ; we use the
Pavement design
Catalogue and obtain
thickness of all the layers
required in the Road.
N = {365*(1+r)^n -1} *D*F*P(1+r)^x
r

6. The portion to be widened beyond the existing crust
was excavated using the excavator.

7. The GSB was brought from the mixing plant in Dumpers and Dumped
at the Site. It was then spread uniformly with the Motor Grader
• The GSB was then
compacted in layers such
that each layer did not
exceed 100 mm compacted
thickness.
• Next the layer of WMM was
spread over the GSB and was
compacted in layers.
• To fill the voids remaining,
stone dust was used, rolling
was continued until no more
dust could be forced into the
voids.
•Sprinkling of water is done
with continued rolling to
obtain well bounded and
firmly set surface.

8. Compacted WMM is allowed to completely dry and set before
the next pavement is laid.

9. Surface of WMM
is swept clean
and dust is blown
of using
compressed air.
Once the surface
is clean, the
Prime coat is
sprayed over the
surface using
sprayer. The
surface is allowed
to cure for 24
hours.
After 24 hours the Tack coat or binder is uniformly sprayed over the
surface. Emulsion is used as binder shall have temperature 20 c to 50 c.

10. Immediately after spraying the tack coat, the layer of BM is laid over
it. The BM is brought at site by a Dumper, at that time the
temperature of BM should be 120 c.
The Dumper is slowly tilted over the Rack of the Paving machine
while both paver and dumper slowly moves forward.

11. The conveyor Belt arrangement in the Paver and leveling plate spreads
the BM neatly behind as both Dumper and paver moves forward. The
Camber is provided by adjusting the leveling plate.

12. Paving is accompanied with rolling. Any high spots or depressions
noticed are corrected by removing or adding material and rolling done
over it again. Water is sprinkled over roller wheels to prevent sticking
of materials to it.
Rolling must be complete before the temperature of BM falls below 90 c

13. A tack coat is again applied over the BM course. The top wearing
course of SDBC is also applied with the same process as BM.
Tolerance level for BM = 6mm
Tolerance level for SDBC = 4 mm
The rolling is done as such
each pass overlaps with at
least one third of the track
made in preceding pass.
The layer of SDBC is
immediately sprinkled with
Stone Dust to prevent the
sticking of materials to shoes
or wheels.
Traffic is allowed 24 hours
after laying SDBC

14. Hot Thermoplastic compound is used for marking, which is laid with
the help of a Road Marking Machinery.
Thermoplastic material is homogenously composed of pigments,
reflecting glass beads and resins.
Binder - 18%
Glass beads - 40 %
Titanium dioxide - 10%
Calcium carbonate - 42%

15. Mostly two types of culverts were constructed along the
road. RCC Culvert and Stone Masonry Culvert.

16. First excavation pit for the Foundation slab was dug. Foundation slab
for both the abutments were casted as one unit.
Series of parallel bars 8 mm dia @
200 mm c/c are laid on the slab
First 400 mm of the bar is made to
rest on the slab and rest part is
folded above at right angles.
These bars are called Skin
Reinforcement.
Formwork for further casting of
substructure is fixed.
Casting is done in two layers of 200
mm, hence casting of 400 mm was
done in one day.

17. According to the shape of the abutment, the skin reinforcements
were bent at the desired angle where ever necessary , fixing of
formwork and casting was done as usual.

18. At 0.5 m above the ground level, weep holes are provided.
Weep holes drain the water that accumulates on either side of the
abutment. Diameter of weep holes = 75 mm @ 1m c/c
The construction till Dirt wall is completed in following the usual
procedure.

19. Lets see how Stone masonry Culvert was completed till here.
Stone Masonry Culverts are built where good quality stones are
readily available. Stones of standard size are joined using mortar
one by one.

20. • A string is stretched along the
length of the culvert which is used to
keep the alignment of the stones
correct while placing them.
•The stones are placed at the edges
first, the flat surface of the stone is
kept facing outward to get a good
finished surface.
• Weep Holes are provided in
the same way as in RCC Culvert.
Dirl wall is also made up of
stones, smaller size of stones
are used in it.

21. After construction till dirt wall is complete, the process for further
construction in both types of Culvert is same.
o The reinforcement for the
abutment cap is tied and form
work is fixed.
o Then casting of abutment cap
is done.

22. o Abutment cap is cured for at least
1 week then the formwork for slab
is fixed.
o The reinforcement for slab is tied
while keeping the necessary
camber.
o Concreting of slab is done as
usual.
o The slab is now cured for 28 days

23. • The old bridge was narrow,
damaged and insufficient to
carry present traffic load.
• It was a five span bridge with
total length 123 m.
• Hard strata was found at a
depth of 20 m
• The construction was just
started and the location of first
pile was well marked.
• A metal sheet was folded with
the help of a machine into a
desired diameter of 1.2 m.
• This metal cylinder was used
as a casing for the pile

24. • A large tripod is centered
over the point of piling
• The cylinder is driven at
that point and water is filled
to make the strata loose.
• Next a pile hammer is
mounted over the tripod
with a system of pulley and
cables.
• The diameter of the
hammer is just enough to fit
in the casing.
• The hammer is then
constantly made to drop
from a height of 5 m inside
the casing.
• This breaks the strata
below.

25. • When enough strata is
broken down, the mud
collected inside the pile
gutter, is taken out with
the help of one way
valve.
• This process is
continued and it takes
near about 5 days to
complete the excavation
of 20 m.

26. • The reinforcement bars are
then tied
• 30 bars of 25 mm dia were
provided as main steel
• Helical Stirrups are provided
of dia 10 mm with a spacing of
150 mm c/c.
• This reinforcement is then
placed inside the pile casing
with the help of a crane.
• Concrete is then placed inside
the pile with Tremie method.
•The tremie pipes are coupled
together and inserted inside
the pile.
•It is fitted with a Hopper on
top.

27. •The concrete is placed on the
top of the Hopper.
• whole length of pipe is filled
with concrete.
• The tremie pipe is lifted up
and a slight jerk is given by
pulley and cable arrangement.
• The concrete gets discharged
in the pile, the end of the
tremie pipe remains dipped in
the concrete so no mud enters
the tremie pipe.
• This method is continued until
concreting for whole of the pile
is complete.
•The concrete does not get
affected due to mud except the
top layer.