This is the eighth edition of CSA A14, Concrete poles. It supersedes the previous editions published in 2000, 1979, 1965, 1959, 1953, 1939, and 1924.
When the first edition of this Standard was published, wood poles were always specified by class, and the class number implied a certain bending strength. This was the only structural property quantitatively defined. Because concrete poles were considered at that time to be alternatives to wood poles, the first and all subsequent editions of this Standard also included the concept of definition by class for concrete poles. Although the class values were different from those used for wood poles, the principal structural property defined was still the ultimate lateral force bending the pole.
Experience has shown that defining strength by class and appropriately labelling the poles is useful to both manufacturers and users. This edition still includes the classes that the earlier editions referred to, and the class tip loadings have not been changed. Users accustomed to buying poles by class will be able to continue to do so, in accordance with their previous practices.
However, there are now many new applications for which the utilitarian class definition, by itself, is not sufficient. In the seventh edition of this Standard, clauses were added so that purchasers requiring poles with higher-than-normal torsion, durability, or stiffness or with ornamental finishes could define their special needs and still purchase a pole that met the requirements of that edition. The same approach is followed in the current edition of this Standard.
As was the case with previous editions, the current edition of this Standard does not address how the strength or other properties of a particular application should be established. Designers of installations need to rely on their own expertise or the expertise of others to determine such requirements.
This Standard was prepared by the Technical Committee on Concrete Poles, under the jurisdiction of the Strategic Steering Committee on Concrete Structures, and has been formally approved by the Technical Committee. It will be submitted to the Standards Council of Canada for approval as a National Standard of Canada.
This Standard specifies requirements for the design, manufacture, and quality control of all types of concrete poles.
This Standard applies to poles manufactured using the casting and spinning processes.
This Standard does not address the rules for
(a) determining the required strength or other functional properties of pole applications; or
(b) choosing a particular class of pole or property of a pole.
This Standard addresses certain special structural, architectural, and other functional properties of
(a) extra-stiff poles;
(b) ornamental poles;
(c) high-torsion poles;
(d) poles subject to severe exposure; and
(e) poles with specified cracking loads.
This Standard does not address the vertical load capacity of poles.
Note: Concrete poles have a substantial, inherent vertical load capacity, which, in general, is much larger than that of wood poles. Annex A provides formulas for calculating the vertical capacity under different conditions of restraint. When the conditions of restraint are known, a manufacturer can supply a pole of suitable proportions, but this is a contractual matter beyond the scope of this Standard.
In CSA Standards, shall is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the standard; should is used to express a recommendation or that which is advised but not required; may is used to express an option or that which is permissible within the limits of the standard; and can is used to express possibility or capability.
Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material.
Notes to tables and figures are considered part of the table or figure and may be written as requirements.
Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.
This Standard is written in SI units, with approximate soft conversions in yard/pound units offered in parentheses for convenience. However, because of the existence of numerous poles made to classes specified in yard/pound units and because the industry is familiar with empirical rules for choosing poles in accordance with these existing classes, the class strengths specified in Table 1are based on the traditional values expressed in pounds and the SI values are soft-converted from the yard/pound units.