PRESTRESSING

Anchorage

We being the pioneer in pre-stressing activities, have the necessary manufacturing infrastructure for supplying all types of components required in pre-stressing operation. Our anchorages are suitable for both round & flat type tendons. The anchorage set, comprising of Tube Unit, Sheathing Pipe, Bearing Plate and Ancharite Wedges are used in post-tensioning jobs; Wedge-grips and Barrels are used in pre-tensioning, both are well accepted world-wide for best in class quality.

Our anchorages are suitable for :

Round Tendon Systems - required in heavy civil structures like Metros, Flyovers, Bridges, Silos etc.

• a) 4T13,5T13,6T13,7T13,8T13,9T13,12T13,19T13,22T13,27T13 – FOR 12.7MM LRPC STRAND.
• b) 4T15,5T15,6T15,7T15,8T15,9T15,12T15,19T15,22T15,27T15 – FOR 15.2MM LRPC STRAND.

Flat Tendon Systems – required in PSC Slab Projects like Building Projects.

• a) 3T13, 4T13, 5T13 - FOR 12.7MM LRPC STRAND.
• b) 3T15, 4T15, 5T15 - FOR 15.2MM LRPC STRAND.

Equipment

Pre-stressing activity call for deployment of various hydraulic and pneumatic equipment at the project site which have to perform with great accuracy and time bound performance.

We manufacture various Hydraulic Equipment:

Hydraulic Jacks

• Mono Jack
  • J-30 (30MT Capacity)
  • J-20 (20MT Capacity)
• Multipack Jack
• Wire Jack

Powerpacks

• Hydraulic press (500 & 1000 MT capacity with accessories and spares)

Grout Pump & Grouting Agitator

Service

Pre-stressing activities requires supply of anchorages, LRPC strand and on-site stressing services. Pre-stressing encompasses pre-positioning & post-positioning both internal and external. Usha Martin has a wide spread set-up for undertaking all types of pre-stressing jobs. Pre-stressing activities generally comprises of profiling pre-stressing tendon at the time of casting, stressing on achieving the strength of cast structure and grouting to remove the void spaces, thus making the tendon integral to the cast structure.

All the above activities are executed by UML expert site personnel using sophisticated hydraulic and pneumatic equipment, which are also manufactured in our state-of-art manufacturing plant located at Ranchi in India.

UML executed various pre-stressing activities for numerous applications like Buildings, Nuclear Reactor, Elevated Structure including Cement and Clinker Silos, Metro projects, Extra dosed bridges, Gigantic water tanks on desert area, Ground anchoring in Dams, Rock fall arrester, Soil Stabilization, High speed Railway projects and RRTS projects.

Usha Martin service team has a vast experience to execute all pre-stressing activities in many of such prestigious projects both in India and abroad.

Testing

We have the following testing facilities at our Ranchi plant both for pre-stressing materials and LRPC strand:

• Anchorage Efficiency Test (Please refer to attached photo in separate folder)
• Load Transfer Test (Please refer to attached photo in separate folder)

Both the above tests are conducted as per FIP 1993 and BS 4447:1973.

Quality System

Special quality system testing is undertaken to manufacture high quality LRPC strands, which are best in its class.