Project specifications often require that individual strands of stay cables be inspectable and, if necessary, replaceable. For these requirements, DSI developed the DYNA Grip ^® Anchorage, which provides the opportunity to inspect individual strands without damaging the stay cable and to replace strands if necessary.

The DYNA Grip ^® Anchorage consists of an anchor block in which the strands are anchored by 3 part-wedges with high dynamic performance. A ring nut is threaded on the anchor block to transmit the cable force via the bearing plate into the structure. A steel pipe, which incorporates centering and sealing provisions for the strands, is welded to the anchor block.

Fatigue tests have proven a dynamic stress range of up to 200 N/mm² (upper stress 0,45 GUTS at 2 million load cycles). Tests with 0.6° inclined anchorages according to the new fib bulletin 30 were also successfully performed.

Special features of the DYNA Grip ^® Anchorages:

• the factory applied corrosion protection of the PE-coated strands continues directly up to the wedges. This significantly reduces the space in the anchorage which is to be filled with corrosion protection compound and improves durability.
• exact cutting to length of the strands and removal of the PE coating is not necessary. The PE-coating is removed using a DSI developed, patented procedure during the first stressing. In cases where subsequent stressing actions are necessary, the remainging PE-coating is compressed by the compression tubes held by the wedges, while the strand is pulled through and elongated by the jack.
• restressing and replacement of individual strands as well as of the complete cable is possible.

Similar to the DYNA Bond ^® Anchorage, an elastomeric bearing is installed at certain distance away from the anchor block to reduce the bending stresses in the strand caused by cable rotation.
A clamp, installed after stressing on the strand bundle, keeps the strand in a compact hexagonal pattern and acts as a support for the elastomeric bearing. In the drawing above, a version is shown that is able to accommodate construction tolerances between the cable axis and the axis of the recess pipe.