Structural designers say there is cause for concern but no reason to panic over research that indicates potential for premature failure of flat-plate concrete frames reinforced at slab-column connections with a popular shear-studs-on-a-rail detail.

Engineers estimate that in seismic zones alone there are tens of millions of sq ft of flat-plate systems reinforced using shear studs. The extent of their vulnerability to punching shear failure is still unknown.