It seems to me that this discussion is missing one important distinction -
guyed tower vs self-supporting. The latter puts much more strain on the base
and any embedded foundation pieces, while the load from a guyed tower is almost
all vertical compression. One former denizen of this reflector had several
fairly tall Rohn 25 towers simply footed in gravel. Our old ham club had a
short one (20')mounted on top of a building in DC with the base simply guyed
across the roof to several vent pipes , to keep it from popping out (yes, we
WERE nuts), considering the liability implications, but this was the 70's)
73, Pete N4ZR
At 09:05 PM 8/28/2006, NØATH wrote:
>At the KCPL power plant where the concrete stacks are 750 feet tall - they
>said
>the magic number for max strength was 28 days. A lot of difference between
>a
>750 stack and a short foundation though. Not trying to add fuel - just
>commenting
>Dave / NØATH
>
>
>
>I would say one week is not enough, remember the compression/tension from a
>tower in wind is a lot more stressful than foundations. I think you are
>guessing, the people who poured my concrete said they always recommend 3 to
>4 weeks for towers or longer for complete curing.
>
>Mike
>
>
>Most builders will cap a foundation within a week of a pour.
>
>Lots of them will start framing at the same time. My sense is a week
>is good enough.
>
>
>
>_______________________________________________
>
>
>
>_______________________________________________
>TowerTalk mailing list
>TowerTalk@contesting.com
>http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________
_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
|