Concrete are at present not used extensively for distribution purposes in the United States. They are, however, used extensively in Europe and other lands where woods suitable for poles are not readily or economically available.
Concrete poles are usually used where great strength and appearance are paramount requirements; concrete poles are made in several colors and finishes.
Concrete poles come in cross sections that are circular, square, or polygonal (usually six- or eight-sided). Both allow electrical risers to be installed in the hollow space within them.
Concrete poles are manufactured with hollow cores to reduce their weight, which has been (and still is) a disadvantage, especially when they are handled in the field.
Reinforcing steel strands are installed longitudinally for the full length of the pole and prestressed before the concrete is placed;
reinforcing steel strands are also installed, essentially at right angles to the longitudinal reinforcing strands, usually as special coils wrapped around and welded to them in a manner to prevent movement during concrete casting. See Figure 10-2.
In addition to their heavier weight (compared with wood), concrete poles are relatively more expensive, another reason for their lessened usage.
All concrete poles are tapered, and the square ones have chamfered corners. All provide cable entrance openings and hand holes to permit the installation of electric riser cables in their hollow cores.
Advantages
Concrete poles are not adversely affected by wet or dry rot, birds (especially woodpeckers), fire, rust, or chemicals (such as fertilizers and salt spray).
Besides being stronger and more rigid than wood, they are essentially maintenance-free; ground moisture and weather, which work against other types of poles, work in favor of concrete, hardening, toughening, and protecting its integrity.
Considering the potential lifespans, concrete claims the lowest cost per year.
Concrete poles are usually used where great strength and appearance are paramount requirements; concrete poles are made in several colors and finishes.
Concrete poles come in cross sections that are circular, square, or polygonal (usually six- or eight-sided). Both allow electrical risers to be installed in the hollow space within them.
Concrete poles are manufactured with hollow cores to reduce their weight, which has been (and still is) a disadvantage, especially when they are handled in the field.
Reinforcing steel strands are installed longitudinally for the full length of the pole and prestressed before the concrete is placed;
reinforcing steel strands are also installed, essentially at right angles to the longitudinal reinforcing strands, usually as special coils wrapped around and welded to them in a manner to prevent movement during concrete casting. See Figure 10-2.
In addition to their heavier weight (compared with wood), concrete poles are relatively more expensive, another reason for their lessened usage.
All concrete poles are tapered, and the square ones have chamfered corners. All provide cable entrance openings and hand holes to permit the installation of electric riser cables in their hollow cores.
Advantages
Concrete poles are not adversely affected by wet or dry rot, birds (especially woodpeckers), fire, rust, or chemicals (such as fertilizers and salt spray).
Besides being stronger and more rigid than wood, they are essentially maintenance-free; ground moisture and weather, which work against other types of poles, work in favor of concrete, hardening, toughening, and protecting its integrity.
Considering the potential lifespans, concrete claims the lowest cost per year.
No comments:
Post a Comment