Engineering360: "Cathedral-Inspired Design Yields Lightweight Floor Slabs"

A resurrection of the 3-D spider web ideas from the early days of FEA. Structurally, it works, certainly with a gross span to depth ratio of no more than 10:1. Lacking ductile tensile bolstering of tension stress zones, though, a concrete only structure is still severely controlled by the tensile stresses in the concrete, a material which, when it does break, does so violently and without the ductile failure of e. g. steel, which failure mode can give a further, albeit, minor margin of safety and warning.