Prestressed concrete is a method for overcoming concrete's natural weakness in tension.. Prestressing tendons (generally of high tensile steel cable or rods) are used to provide a clamping load which produces a compressive stress that offsets the tensile stress that the concrete compression member would otherwise experience due to a bending load.

The technique of prestressing is one of the recent developments of concrete constructions and is particularly suitable for the manufacture of concrete pipes. The most outstanding property of P.S. concrete is its very high resistance to cracking. This feature is of great importance in water pipe line.

It can be used to produce beams, floors or bridges with a longer span than is practical with ordinary reinforced concrete. P.S.C Pipes serve as a critical input for wide range of applications such as water supply; lift irrigation and drainage schemes which involve high pressure.

Design:
PSC Pipes are manufactured using the similar fundamentals as RCC Pipes. However, before concrete mix is fed into the rotating moulds, longitudinal wires of specified diameter and length are placed between two end rings of the mould. These wires are stretched to reach the requisite tension after which the centrifugal casting is done. The core pipe that is produced is wrapped with a high tensile wire using a wire winding machine, followed by a dense cement mortar coating. The cured pipes are subjected to a hydrostatic pressure test.

Key Raw Materials:

1. Cement
2. High Tensile Wire
3. Stone aggregate

Experience:
Date of commencement of production: June 5, 2003
Capacity as per BIS License at that time:
350mm, 450mm, 500mm, 600mm, 700mm, 900mm
Capacity as on date as per BIS License:
300mm to 1600mm

The prestress concrete pipes are manufactured in line with the IS Standard specification No.784-2001. Comparatively new in this line of product, CUL has picked up significant projects in areas of Uttar Pradesh, Madhya Pradesh and Haryana. The pipes laid down has been reportedly servicing satisfactorily without breakdown or corrosion.