The issue really is bad joint design in an area where even a single failure is unacceptable. They should have used J- hooks, or some other type of positive mechanical connection to the steel structure. Suspending the weight of a tractor trailer using threaded rods epoxied into blind holes? Sombody watched too many Krazy Glue commercials.
There are so many factors that go into designing, producing, and qualifying high reliability adhesive bonds, that it just seems foolish to have allowed their use here.
Caulking should not be used in lieu of weather closure, an epoxy set anchor should not be placed in tension, and existing sub-soils should be proof rolled.
This was a design error before any error first and foremost.
If for some highly unlikely reason it was necessary, then special care in the specification of the material including a sample test and frequent field tests should have been specified.
Often times the trade contractor in the field has three days to order out the material needed for a procedure where the designer has three years to select and specify it.
Don't get me wrong, I've seen small plumbing contractors paint a fitting a bright copper color to try and make a stupid substitution out os stupid attempts to not have to stop work and pay for the right part, but this smacks of the threaded rod design on the Hyatt Regency Skywalks collapse.
Threaded inserts should have been placed in the concrete before the concrete was poured, but given the way the design was done on the fly, the epoxied anchors should have held if properly specified and installed. The design sucked, becaus e there was not enough redundancy or factor of safety, obviously.
They are used successfully in mining applications all the time. For the ignoratti here, there is epoxy and there is epoxy. using a formulation not designed for the application is the culprit.