Fill pipes with Sand instead of concrete and the shrikage problem is solved
and it makes a great sound dampener.


----- Original Message -----
Sent: Monday, July 23, 2001 1:15 AM
Subject: [M]: Re: RE: [LX-200] Piers, again


> Careful with filling the pipe with concrete, as it can shrink when it
cures,
> leaving a gap between the concrete and the steel pipe, thus letting it
carry
> vibration again.
>
> From my experience, the wetter the mix the greater the shrinkage. It can
> often be tempting to wet the mix to make it more pourable, but this can
> cause problems later with shrinkage and reduced strength.
>
> Would the extra weight cause problems for your footing? It may cut the
sway,
> but you end up with a long term lean developing, esp if the dirt around
your
> footing gets wet.
>
> There are bonding agents to help new concrete stick to old. Make sure your
> old concrete is clean and roughened up to give some purchase. Chip it up
> with a chisel or jackhammer and if you still have any doubts, drill some
> holes and stick in expanding bolts to act as reo.
>
> A cheaper solution: If you've got room for guy wires, try using 1/2 to 3/4
> inch steel rod instead. Thread it at each end and then you can use
adjusting
> nuts to pull it all very tight. Would make it all very rigid. The rods
could
> also be used to give you final adjustment for alt/az.
>
> Good luck
>
> Colin James
>
>

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