Shear key in thick elevated slab, acceptabe? 1

[IJR]

I have to anchor a truss on top of a thick elevated slab.

Horizontal reaction is very high. Instead of anchor bolts I have elected to use a couple of shear keys(profiles attached to base plates and embedded into concrete, to be grouted later)

This will eat up some thickness of the slab.

How bad is this imagination of mine?

regs
IJR

 

[ishvaaag]

It may work but both analysis and execution need be undertook with care. Embedded C connectors had once defined their shear strength for composite beams (typically used at ends), and of shear lugs the baseplate publication of AISC had something about.

Then yours are inserts, so one likely would think in degraded strengths for the thing. Some trapecial shape of the key may be required, and good and special mortars of nil retraction maybe also with special adhesive preparations of the surface.

You may as well pierce the whole slab and then lock from below if the space is available, for an entirely understandable even if simplified introduction of the load. If close to an edge, do not for get to check if spalling will be induced by any outwards force.

 

[IJR]

Ishvaag,

thanx for the lightning fast resp. I am now also interested in the adhesive used with the grout(mortar). Wanna talk about that?

respects
IJR

 

[ishvaaag]

This thing better be done under the sight of one provider of special mortars as Sika or similar. Clean, stout and dry surfaces will be mandatory as ever adhesion is important. And mortars of methyl methacrylate polymer attain over 100 kgf/cm^2 shear strength or 3 times that of basic concrete, so it is clear that the adhesive binding agent within must be great about any adhesion task with improvement of the sehar capacity. It also stand ample range of temperatures with improved shear capacity. To have extant bars binding your anchoring block to the slab if feasible will be good.