PROTECTION OF THE CABLES WITH HDPE (HIGH DENSITY POLYETHYLENE)
HDPE (high density polyethylene) is an external sheathing that provides a further security in addition to the inner filling and the zinc-aluminium
coating on the outer wires of the cables, assuring optimum durability of cables even in very aggressive environments.
HDPE protection is nowadays the most durable corrosion protection for stay cable bridges and other applications on civil engineering structures.
HDPE protection is applied by hot extrusion, as high density polyethylene sheath on the cable.
The sheething is designed to have the best UV stability against sun radiation and weathering resistance and it can be produced with outer finishing coloured as per client’s requirement.
Raw material suppliers selected by Redaelli are worldwide primary producers.
HDPE sheath on the cable maintains the capability of the cables to be coiled on a diameter of 30 times the diameter of the cable.
In order to protect the HDPE sheathed cable also at the connection to connection to the socket, the socket bottom part is designed so that it creates
a watertight joint which seals the entrance of the cable.
The HDPE has the following properties:
- Elongation at break: 400% min, ISO 527
- Yield Strength: 19 MPa min, ISO 527
- Elongation at Yield: 8 % min, ISO 527
- Density: 0.94÷0.96 g/cm3, ISO 1183
- Excellent ESCR properties: 1000 h, ASTM D 1693.