MENU

Ibdm bridge pre-stressing system for multi-strands

Bridge prestressing system especially for external cables
for reinforcement of existing/construction of new bridges.
prolongation of structure exploitation due to better anti-
corrosion protection and cable inspection system.

The Bridge Prestressing System is designed for strands 15.5 mm in diameter. The number of strands varies from 3 to 19 and even more if there is a need for a bigger prestressing tendon. All anchorages are designed to the same principles, varying only in the numbers of strands. Each consists of a steel guide incorporated in the structure which distributes the tendon force into the concrete endblock. On the guide sits the steel anchorage block into which the strands are anchored by means of three-piece jaws, each locked into a tapered hole. The anchorage block is designed to allow an increased prestressing force under exploitation should such an need arise. The structure of anchorages and all of the superstructure of the bridge provides an easy way to replace the tendon by a new one after years of work. The additional devices in the cables allow for easy control and record of prestressing force under exploitation of the structure. In this way the real structural life of the bridge may be essentially extended and this is the main advantage of the project. The sheath is designed as a polymer tube of the proper diameter with a very low friction coefficient to reduce prestressing losses. Anchorages are mechanically protected against strand slippage under exploitation. In this way it is possible to use bituminous injections with a special chemical ingredient as a protection against tendon corrosion. A special type of deviator assures the proper radius of tendon at each deflection. The system is designed as a safe prestressing method for structures working under repeated loading. The maximum breaking load of cable depends on the number of strands and for 19 strands it is about 4500 kN.
Acronym: 
BRIDGE PRESTRESSING
Project ID: 
1 740
Start date: 
01-07-1997
Project Duration: 
24months
Project costs: 
1 000 000.00€
Technological Area: 
Market Area: 

Raising the productivity and competitiveness of European businesses through technology. Boosting national economies on the international market, and strengthening the basis for sustainable prosperity and employment.