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 timber workshop.

The 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.

HPL 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 quality.

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.

Casting 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.