DYWIDAG El-Iso Strand Anchor

Specialist anchor for applications requiring a higher level of verification.

The DYWIDAG Electrically Isolated Strand Anchor has the same make-up as the Permanent Strand Anchor system, but with isolation components used to separate the anchor head componentry from the bearing plate, which sits on the structure.

Electrically isolated systems may provide the client with a further check to prove the integrity of the corrosion protection barriers between the anchor tendon and the environment. The integrity of the corrosion protection barrier is measured by the electrical resistivity between two probes, one on the anchor tendon, the other in the ground. In practice, the measurement of the resistivity levels is highly subjective as there are a number of variables, i.e. moisture level, precipitation, contact between probes, and measuring equipment used. As a result, the test result can vary.

The application of Electrically Isolated Anchors may ensure a higher level of care and quality during installation in certain markets.

It is important to prove the integrity of the anchor sheathing at the time of manufacture, delivery to site, and upon installation.

  • Isolation sleeves and washers are integrated with the anchor head componentry to ensure isolation of the anchor tendon from the bearing plate for testing purposes.

  • Anchors are supplied as single section, and are fully coiled for ease of transportation and site handling

  • Particularly suited to low headroom or restricted access locations due to the flexibility of the tendon

  • Anchors can be grouted in-situ or supplied factory pre-grouted, dependent on site restrictions and grouting capabilities

  • Anchor head componentry can be tailored to specific applications, e.g. re-stressable or de-stressable

  • Permanent systems feature double corrosion protection (DCP) to ensure durability throughout the lifespan of the installation

  • Anchor head protection for permanent works comprises specialist anchor protection caps and sealing arrangements to ensure a long service life

Main standards for steel nuances

Europe/ Asia/ Latin America: Steel Strand Ø 15,2mm (0.6 in) and Ø15,7mm (0.62 in) – 1 to 22+ strands

UK: Steel Strand Ø 15,2mm (0.6 in) – 1 to 27+ strands

North America: 7-wire, low relaxation 270 ksi Steel Ø 0.6 in (15,2mm) – 1 to 61 strands


  • Bearing plates with angle compensation, different finishes, architectural features.

  • Borehole spacers : lantern or skid

  • Tremie tubes for borehole grouting (bottom up)

  • Post-grouting tubes complete with TAM (tube à manchette) valves for bond stress enhancement

Industrial Buildings
Commercial & Residential Buildings