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Re: [TowerTalk] Welding re-bar, preventing corrosion

To: "Red" <>
Subject: Re: [TowerTalk] Welding re-bar, preventing corrosion
From: "Rick Karlquist" <>
Date: Fri, 7 Jul 2006 14:59:19 -0700 (PDT)
List-post: <>
Red wrote:
> It is important that no steel penetrate the concrete below grade.  A
> penetration provides a path
> for the natural alkalinity of concrete to leach out, thus losing some of
> the anti-corrosion
> protection that concrete provides to steel.  Bring grounding terminals out
> of the concrete above
> grade.

Let me make sure I understand this correctly.  A piece of rebar
poking out of the concrete below grade will rust.  A piece of
steel poking out above grade will not rust?  Why is this?  Is it
moisture related?  The stuff above grade will still get wet
whenever it rains or there is dew.

This brings up the question of anchor bolts:  galvanized or black
steel?  I notice that UST supplies non-galvanized bolts.  However,
every streetlight I've seen uses galvanized bolts.  According to
what you say, the black steel is OK on account of it being above
grade.  Right?  I noticed that the UST bolts are already rusty
when you get them from UST, not to mention what happens after the first
rain.  Any advice here?

> To prevent penetration, place concrete "pills" at least 3" thick
> under the steel at the
> bottom before pouring the concrete.

When you go to the store, ask for "dobies" not "pills"
(and not "doobies" either :-)

Rick N6RK

> 73 de WOØW


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