Epoxy Anchor Issue
Epoxy Anchor Issue
(OP)
I am woking on a job where I specified Simpson SET epoxy for some shallow, 1/2" anchors (2 1/4" embedment due to embedded slab items). I used the Simpson tables which gave me an allowable pullout of of 1805 lbs (ASD) at 2 1/8" embedment in 2000 psi concrete. The contractor used Hilti RE100 instead. Their tables do not go below 2 3/4" embedment with no reductions allowed. The owner is asking for an appendix D calc. The epoxys are similar with the Simpson bond being 10% stronger (3300 psi versus 3000 psi). My demand is only 1400 lbs (ASD). I assume concrete breakout is the actual failure mode so the bond strength should not be an issue. Is it reasonable to assume that the Hilti product will perform similarly.
Thanks
Thanks






RE: Epoxy Anchor Issue
RE: Epoxy Anchor Issue
RE: Epoxy Anchor Issue
RE: Epoxy Anchor Issue
FWIW, the bolt is being used at the base of a moment clip to anchor some sill studs. I wonder if that will help as the the clip adds a compressive load to the top of the concrete under overturning (see attached)
RE: Epoxy Anchor Issue
Please note the strength I am talking here is the concrete strength, see the picture for information about breakout failure and group reduction conception.
RE: Epoxy Anchor Issue
RE: Epoxy Anchor Issue
I think the effectiveness factor, kc, for Simpson Set XP in uncracked concrete is 24 rather 17 used in your calculation. If that is not the case, Simpson may be increasing the capacity for uncracked concrete by using Ψc,N = 1.4. But if you are like me, you always assumed the concrete may become cracked.
RE: Epoxy Anchor Issue
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
RE: Epoxy Anchor Issue
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RE: Epoxy Anchor Issue
The bolts will be installed 2 3/4" clear from the slab edge. Shear due to wind toward and away from the slab edge is my only load. Due to the close edge distance, the capacity of a 3/8" epoxy anchor is quite low (about 450 lbs ASD). Do you think I can take into account confinement in the concrete due to the slab edge angle? I realize this would be an engineering judgement, but any thoughts?
Thanks
RE: Epoxy Anchor Issue
RE: Epoxy Anchor Issue
Thanks
RE: Epoxy Anchor Issue
RE: Epoxy Anchor Issue
They go in a light gage clip at the window jambs.
I am using those in other locations but they have spacing issues in this situation. I may look into adding them.
FWIW, I talked to some former colleagues and they feel the edge angle will prevent a shear blowout
RE: Epoxy Anchor Issue
RE: Epoxy Anchor Issue