Re: Pier Construction


Tim Khan
 

--- Mark Jenkins <markj@pcsincnet.com> wrote:

The sonotube/concrete only solution has me worried
about cracks in the
concrete where the bolts protrude. Are these fears
unfounded?

Just a note on sonotube/concrete:

Concrete cracking around the bolts are due to, a
couple of items. First cracking is ussually due to too
much water in the mixture (shrinkage during curing),
use between .25 to .35 water to cement ratio.
Secondly, be sure that you use horiz. reinforcing like
#3 ties at 8" and where the anchor bolts are use #3
ties at 4" to increase the confinment.


--- Mark Jenkins <markj@pcsincnet.com> wrote:

I posted this to alt.binaries.pictures.astro but
have yet to get a response.

Looking for any and all advice for constructing my
permanent pier.

Is a solid concrete pier better than a steel tube
set in concrete?

Initial thoughts are:

Dig a 4' x 4' hole 7' deep.

Pour 1' thick of reinforced concrete with 4 "J"
bolts set in the concrete.

Fabricate a steel pier that is constructed using a
8" - 10" mild steel tube
5/16" to 1/2" wall thickness with a 3/4" x 2'
square plate on the bottom.
Paint with industrial grade epoxy both inside an
out. Use the bolts at the
bottom of the now 6' deep hole to secure and level
the pier to the footer.
Fill the hole with reinforced concrete and let cure
for about a week. Fill
the steel tube with concrete and let cure. Weld a
3/4" steel plate on top to
be used to fine adjust the level of the Meade
SuperWedge or AP 400GTO that's
due in July, or future AP mounts like a 600 or 900.

Or...

would it be better just to pour concrete in a
sonotube with bolts at the
top?

Looking for a proven design and willing to go to
extremes to assure complete
stability.

The sonotube/concrete only solution has me worried
about cracks in the
concrete where the bolts protrude. Are these fears
unfounded?

Thanks.

--
Mark Jenkins
markj@pcsincnet.com
http://www.pcsincnet.com/astronomy/



------------------------------------------------------------------------
Save up to 57% on Electronics!
Find incredible deals on overstocked items with Free
shipping!
http://click.egroups.com/1/2710/3/_/3615/_/954644331/

-- 20 megs of disk space in your group's Document
Vault
-- http://www.egroups.com/docvault/ap-gto/?m=1

__________________________________________________
Do You Yahoo!?
Talk to your friends online with Yahoo! Messenger.
http://im.yahoo.com

Join main@ap-gto.groups.io to automatically receive all group messages.