Cable anchorage with seal element, prestressing system comprising such anchorage and method for installing and tensioning a sheathed elongated element

A method for installing and tensioning a sheathed elongated element with a sheathed running portion, a first unsheathed end portion and a second unsheathed end portion, said sheathed elongated element comprising a sheath with a first sheath end adjacent to said first unsheathed end portion and a second sheath end adjacent to said second unsheathed end portion, said method comprising the following steps:

• providing for at least the second unsheathed end portion an axial channel extending between a first channel end, proximal to said running part of the elongated element, and a second channel end, said axial channel being equipped with a seal element and with a stop element placed between said seal element and said second channel end, both seal element and stop element defining a passage for the elongated element, wherein the inner diameter (DT2) of the stop element is smaller than the outer diameter (DS1) of the seal element in its uncompressed state,
• introducing, for at least the second unsheathed end portion, the extremity of said unsheathed end portion in said first channel end and axially displacing said extremity of said unsheathed end portion up to the second channel end,
• immobilising the extremity of said first unsheathed end portion with respect to a cable anchorage
• pulling the extremity of said second unsheathed end portion from the second channel end at least until the second sheath end of said sheath end portion abuts against a shoulder of said stop element in order to obtain a tensioned elongated element, creating thereby an abutment position of the elongated element in said axial channel, and
• immobilising the extremity of said second unsheathed end portion of said tensioned elongated element with respect to said second channel end,
• wherein said shoulder is defined at an end of said stop element which faces said seal element, wherein the regions receiving said seal element and said stop element are longitudinally adjacent to each other in the channel, so that, during said pulling step and the axial displacement of said elongated element, said seal element is able to be placed in a longitudinal location adjoining said stop element, with the seal element abutting the shoulder;
• wherein the volume of the recessed region is made such that in said abutment position the sheath end of the sheathed portion is deformed so as to form an outwardly radially protrusion at least partially surrounded by the seal element which is thereby outwardly radially compressed by said deformed sheath end, whereby said deformed sheath end is mechanically anchored inside the recessed region in said axial channel.