Custom Search
|
|
|
||
 Additional fortification (preservative loading) of the original pressure
preservative treatment is one of several techniques used to improve service
life performance when environmental conditions are considered harsh and
contribute significantly to the early failure of wood components or when
treated members must be cut or bored on site. This procedure will increase
both preservative penetration and retention which will, in turn, effectively
protect poles against the sometimes hostile environments to which they are
subjected.
Preservative treatments for new wood products are specified in accordance
with the American Wood Preservers Association (AWPA) treatment
standards. AWPA standard C-4 (POLES) specifies preservative retention
levels in accord with geographical location and associated decay hazards.
As conditions worsen, higher retention levels are specified. At CDAA
sites where poles are subject to extremely hostile environments, due to the
reasons discussed above, even the highest retention level is considered
unacceptably low. Increasing preservative loading to an effective1 level
therefore requires that CDAA poles be specified under the AWPA C-3
(PILE) standard which accommodates the desired loading level. Thus,
CDAA high-band poles to be ordered under this standard are in essence
piles and should be designated (for preservative treatment purposes in
accordance with AWPA Standards) as MARINE PILING.
NOTE:
A CDAA high-band pole treatment
specification which has been tailored
with the above guidelines in mind is
attached as Appendix B.
Wood inspection surveys conducted at
1.5.4 Low-Band Poles.
several CDAA sites throughout the world determined that low-band poles
are performing extremely well, even in the most hostile environments such
as Galeta Island, Panama. Preservative assays were conducted at these
sites. Surprisingly, retention assays for these poles (all creosote preserv-
ative treated) indicated exceptionally high retention levels. Keeping in
mind also that these poles have been in service in excess of 25 years during
which time some preservative leaching has occurred. The exceptional
performance being experienced can be primarily attributed to the superior
preservative treatment of these components. Furthermore, these poles are
1-19
|
 
|
|
|
||
