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Re: ACI 355.2

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Message text written by INTERNET:seaint(--nospam--at)seaint.org
>Question: What restriction if any will be placed on the use of epoxy
anchors

(or other chemical anchors which do not promote concrete cracking from

expansion pressure?
<

I don't have a lot of experience with epoxies, but I believe they will have
a difficult time with this protocol. As I understand it, the anchor is
drilled, set and cured in the concrete specimen with the prentension on it.
The pretension force is then removed and the anchor tested. This will
almost certainly induce a tensile strain on the anchor hole. How well epoxy
tolerates tenstion will determine its performace. The epoxies and acrylics
are not very stong in tension, so I expect their values will be affected.
At least that's what happened in Europe when this thing was adopted. There
was a large hue and cry and the EU has directed a review of the procedure,
with a view to rewriting or eliminating it altogether (the more likely
outcome according to "insiders").

Peter Higgins, SE