Fressinet system of post tensioning
PRINCIPLES OF POST-TENSIONING:
In post-tensioning, the concrete units are first cast by incorporating ducts or grooves to house the tendons. When the concrete attains sufficient strength, the high-tensile wires are tensioned by means of jack bearing on the end face of the member and anchorags by wedges or nuts.
FREYSSINET SYSTEM OF POST TENSIONING:
The Freyssinet system of post-tensioning anchorages which was developed in 1939.
The Freyssinet anchorage system, which is widely used in Europe and India, consists of a cylinder with a conical interior through which the high-tensile wires pass and against the walls of which the wires are wedged by a conical plug lined longitudinally with grooves to house the wires. The main advantages of the Freyssinet system is that a large number of wires or strands can be simultaneously tensioned using the double-acting hydraulic jack.