Strike Anchor Bolts

[406Eng]

So I recently was having a discussion with a friend & fellow engineer (of the civil persuasion) who also moonlights as a pretty good carpenter. We were discussing a stick frame garage he built a couple years ago and he informed me that he had used 1/2" x 6" strike anchor bolts drilled into his slab-on-grade for wall anchorage as a substitute for typical cast in place anchor bolts. He said that he had heard that they provided near equivalent shear, tensile, and tear out strength as "L-hook", "J-hook", and other more standard anchor bolts. A quick search on several manufacturers websites shows values that do seem to be in the ball park for strength but I could not find any further technical data to support the Manufacturers provided values.

I am curious what people's thoughts, opinions, and experiences are with strike anchor bolts in both residential or commercial design.

 

[canwesteng]

Do you just mean expansion anchors? These are very common in residential in my neck of the woods. There won't be any capacities outside of vendor provided ones as they are tested to determine strength.

 

[STrctPono]

Each case is different, but as a general rule of thumb, the capacity of a post-installed anchor bolt will not be as great as it is for a cast-in-place anchor bolt when loaded in tension. Post-Installed anchor bolts get typically lower concrete breakout capacity and pullout capacity than cast-in-place bolts of equivalent diameter and embedment. In shear, the difference is not as drastic but still favors cast-in-place bolts slightly.

You're more than welcome to run through a side-by-side comparison of different anchor capacities by running the numbers per ACI 318-14 chapter 17.

 

[r13]

I believe the strength of post install anchors are tested per governing standards, so don't be surprised that there is lack of literature, or other data available.

 

[XR250]

If is it a 2x4 wall on the perimeter of the slab, the edge distance is so small that the capacity of either is not great. This is how most garages around here are constructed and they don't fly away on a regular basis, however.