[TowerTalk] Rebar

[Jim Lux]

-----Original Message-----
>From: Gregg Seidl <k9kl at centurytel.net>
>Sent: May 29, 2008 12:33 PM
>To: TowerTalk at contesting.com
>Subject: [TowerTalk] Rebar
>
>Concrete will still CRACK with rebar in it but it won't seperate at the 
>crack.The rebar will hold it together.Gregg  K9KL 
>

There are various standards for the maximum crack size where you would declare that "failure" has occurred.

A quick google turns up a standard of 0.01" crack width for concrete pipe, which has been determined (by experiment and analysis) will not allow sufficient water and oxygen penetration to adversely affect the integrity of the reinforcing steel.

Obviously, if you have a concrete structure with a 1" crack that still holding together, it's basically failed (although, presumably in a failsafe or failsoft sort of manner).

Somewhere in between, you'll have a failed structure that is structurally OK today, but won't have the life or longevity in the future.  That's the situation where water infiltrates and causes corrosion of the rebar, then, perhaps lightning induced spalling.

Jim, W6RMK