Anchor breakout, correlating allowable tension with shear

[bhiggins]

Hi eng-tippers!

I have a renovation project where we are installing a large number of anchors into an existing 100+ year old limestone and clay brick wall. The quality of the limestone walls are suspect so I was going to retain Hilti to do a load test on some anchors to verify our design values. Hilti unfortunately only does a tension test and our anchors will be loaded in shear. I was wondering if anyone knows any rules of thumb or equations that would be able to correlate the allowable tension results with shear allowable values? I should also note that edge distance is not of concern.

 

[chris3eb]

The commentary in ACI 318-14 has an explanation comparing shear pryout to tension breakout:

Of course you're not dealing with concrete, so this same relationship may not hold true. There are also other modes of shear failure that this doesn't account for (such as crushing of the substrate near the point of application of the load).

For the load test, will they be able to test the tensile breakout strength (meaning they will not confine the breakout cone and they will load it until a cone pops out), or would they be testing the bond strength only (meaning that the testing apparatus prevents cone breakout)?