HPL has a modern factory
for manufacturing precast concrete products,
which includes the following.
1) Precast prestressed concrete products
like Railway Sleepers and Electric Poles.
2) Autoclaved aerated cellular concrete.
These are light weight yet have sufficient
strength for walling and other applications.
3) Reinforced concrete products like pavements
slabs, frames, water tanks, bridge girders,
interlocking solid blocks for pavement
& for retaining walls, kerb stone etc.
4) Timber joinery components and wood substitute
items manufactured with wood/medium density
fibreboard in the company’s
company pioneered the development of precast
prestressed concrete products in India.
Picture shows stacks of prestressed concrete
Railway sleepers which were developed by
the company. HPL is in the field of producing
pre-stressed concrete components such as
PCC poles, Railway Sleepers, Roof girders
for more than thirty years now.
A large quantity of sleepers required by
the Indian Railways is produced in the factory.
The factory employs the long-line technology.
Sleepers are cast in twin moulds, steam
cured through integrated steam pipes, demoulded
and stacked in large water beds for submerged
curing. These sleepers are then despatched
through the captive railway siding at the
plant itself. The plant has all the facilities
for structural testing of railway sleepers.
Detailed checks are done on batches produced
as per Railway standards before the sleepers
are loaded into wagons.
has so far supplied more than one-and-a
half million sleepers to the Indian Railways.
The Company has twenty one prestressing
tables, each approx. 100 M. long. It has
the distinction of being the biggest prestressed
concrete plant in India. As a pioneer in
the prefabrication of bridges, the company
has perfected the techniques of precasting
heavy prestressed concrete elements.
Experience shows that the precasting of
superstructure reduces the hassles of doing
cast-in-situ work at site and also guarantees
The superstructure are precast in large
tension beds or individual stress benches
depending upon the merits of the case. Tolerances
are very low, since an out of tolerance
work would mean rejection of an entire span.
Concrete is controlled and steam-curing
applied to get fast turn-around of moulds.
Bridge girders, after curing, are transported
in large articulated lorries and stacked
at site. These are then erected on the piers
at later dates according to requirement.
of precast bridge sections requires meticulous
planning and accuracy. The sections are
cast in the factory by the long-line method
and at the site by the stress bench method.
Millimeter tolerances are observed while
concreting. Since any irregularities have
to be rubbed down by grinders, teams of
qualified workmen continuously check for
tolerances prior to casting and apply gauge
checks after casting.
The ultimate quality of the bridge is determined
on the casting table itself in terms of
tolerance maintained. The overall beneficiary
of a precast bridge contract is the client.
Not only does he get the best quality of
workmanship, he also benefits from the short
completion times required for erection,
which enables him to put the structure to
economic use in record time.