VIBRATED REINFORCED CONCRETE (VC) POLES VIBRATED REINFORCED CONCRETE (VC) POLES
GENERAL SPECIFICATIONS (VC)
Our vibrated reinforced concrete poles have a truncated pyramid shape on the outside with an I-type section. The first two metres from the top are a rectangular section, with the rest of the pole being reinforced at intervals of every fifty centimetres, which means that at these points the sections are also rectangular.
The faces on the pole become narrower from the top to the base at a constant rate and which may be different for the narrow and wide faces (See DRAWINGS). This constant reduction in the measurements is:
narrow face: fb = 2 tan a
wide face: fh = 2 tan b
For the sake of convenience, these values are usually expressed in millimetres per metre (mm/m.).
All the other measurements, outer thickness of the flange (t), width of the stem (a), bevelled edges (m), angles (g) and stiffeners (n) remain unchanged along the length of the pole.
ADHORNA manufactures all its mass-produced poles with a safety coefficient against failure through buckling of 2.25 as per standard UNE 207016.
In order to guarantee this coefficient, production control tests are systematically undertaken and the poles are tested through until actual failure.
A concrete pole basically acts as a beam that is subject to stress. As it is not equally resistant due to its shape, there are two main stress areas, which are perpendicular to each other and each one of them contains the directions of maximum (principal or transversal) and minimum (secondary or longitudinal) resistance, respectively. These primary and secondary directions of resistance go by the names of “principal stress” or “transversal” and “secondary” or “longitudinal” which are the ones that cause buckling on the surfaces in question.
Likewise, the wind that acts on the pole’s structure may exert pressure in either of these two directions (principal or secondary).
In order to use a pole with the utmost guarantees by making the most of its strength specifications, one needs to know its resistance limits, not only when it is stressed in the principal or secondary directions, with or without wind, but also when the stress is simultaneous in both directions (cases of imbalances, ends of line with side wind, etc.).
Concrete poles are defined by their overall length and by their nominal force (it represents the free stress available according to the principal direction at a distance of 0.25 m below the top), with those manufactured by ADHORNA being as follows:
Lengths and forces of VC poles |
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Nominal force, F (daN) |
Top measurements (mm x mm) |
Length (m) |
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9 |
11 |
13 |
15 |
17 |
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160 |
110 x 145 |
x |
x |
|
|
|
250 |
x |
x |
x |
|
|
|
400 |
140 x 200 |
x |
x |
x |
|
|
630 |
x |
x |
x |
x |
x |
|
800 |
x |
x |
x |
x |
x |
|
1000 |
170 x 255 |
x |
x |
x |
x |
x |
1600 |
x |
x |
x |
x |
x |
|
Concrete poles are labelled by means of four groups of letters or numbers. These groups of numbers or letters, arranged in the order specified forthwith, mean the following:
• The letters HV (Spanish for VC), indicating vibrated reinforced concrete.
• Figures that represent the value of nominal force in FdaN.
• N or R as appropriate.
• Figure that gives the overall length of the pole in metres.
Example: HV 250 R 11
This serial number corresponds to a vibrated concrete pole with 250 daN of nominal force, reinforced and with an overall length of 11 m.
For the quick identification of the poles, the upper part is painted in the following identifying colour:
| Identifying colour for VC-type poles | |
| Nominal force (daN) | Identifying colour |
| 160 | Orange |
| 250 | Black |
| 400 | Blue |
| 630 | Red |
| 800 | Yellow |
| 1.000 | Green |
| 1.600 | White |
The geometrical and strength specifications of vibrated reinforced concrete poles are as follows:
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