MK4 DMK Stay Cable System
The DMK Stay belongs to the latest parallel strand cable stay generation.
Stay is based on a bundle of self-protected prestressing strands that run inside a global polyethylene duct. Strands are anchored through the wedge system in the DMK anchor heads.
The following premises have been taken into consideration for the DKM Stay design:
- Stay behaviour according to the most relevant international recommendations
- Durability
- Wide size range
- Easiness of installation
- Unitary stressing (strand by strand)
- Adjustable anchorages for full stay stressing or distressing
- Force checking or monitoring at any time.
- Replacement of the stay, as a whole or each strand individually
- Prepared for damper installation
- Adaptable for special solutions
Stay anchor heads have been tested according to the PTI Recommendations for Stay Cable Design, Testing and installation and have achieved the following successfully:
– Dynamic behavior: 2 million cycles, 200 N/mm2, upper load limit 45% GUTS
– Static efficiency: 95% of GUTS (Guarantied Ultimate Tensile Strength)
Basic stay is fully sealed to avoid the entrance of water inside and comprises at least 4 protective barriers to the steel of the strands at any point, this warrants the maximum durability of the tensile element against corrosion.
Standard sizes are composed of 7 to 127 strands with 0.6” diameter.
The strand to be used can either be 15.2 or 15.7 mm. nominal diameter.
The strand holes at the anchor heads and inner deviators are large enough to allow the self-protected strand and its envelope to go through. These characteristics allow the insertion “in situ” of the strands from the outer surface of one of the anchor heads, avoiding the need to pre-cut or pre-peel them before threading. This advantage reduces threading time and considerably makes the stay installation easier. It also permits the replacement of a stay strand by strand as stressed strands do not impede the access or movement of the one being replaced.
All DMK anchorages either adjustable or fixed types, allow unitary stressing with a monostrand jack. This gives freedom to decide where to place the adjustable end for global stay force checking or regulation and where to stress strand by strand.
