Bonded Strand Post-Tensioning System
DYWIDAG has developed a series of jacks, rams and hydraulic pumps in order to reach the target stressing load. The necessary versatility is provided by changing devices that make one unit adaptable for many different tendon sizes. With jack capacities ranging from 250 kN up to 15,000 kN, DYWIDAG Equipment is designed to cover a wide spectrum of applications.
DYWIDAG Rams are highly sophisticated, but still convenient to operate. They employ inner tube bundles with automatic gripping devices that guide the strand safely through the inside of the ram. This feature allows the stressing operation to be controlled with the highest degree of reliability as well as minimal wedge seating losses by benefiting from the power seating option. Power seating is a way of hydraulically pressing in the wedges with a predefined load individually and simultaneously rather than relying simply on friction seating. DYWIDAG Rams also make it possible to overstress and release the tendon to compensate for friction losses and maximize the stress level over the tendon length.
Every ram has a pressure relief valve for safety reasons that activates to limit hydraulic pressure should the hydraulic pump malfunction. To further verify the stressing operation, an additional gauge port is provided directly on the ram.
Stressed tendons can be destressed with special wedges and a special ram configuration. Hydraulic pumps can be equipped with a convenient remote control device.