I seem to remember that's exactly what vault building companies do to make the pre-fab panels,
adding swarf to the pretty dry concrete mix, vibrating the molds for hours.
I did a fast check and that's about what I found.
Thus purportedly getting more 10 times more ruggedness from today's 3" panel than the old 18" conventional concrete pour.
Then as an added benefit - the swarf probably also diverting the heat from a villain's torch -
making the wall "impossible to cut".
What they actually add to the mix is shrouded in the mystery of "proprietary info", of course...
-So, what swarf are they actually using?
Stainless for ruggedness? Aluminum for heat conductivity? "Tungsten swarf", if even existant, for the highest melting point?
Link:
How bank vault is made - material, history, used, parts, product, industry, History, Raw Materials, Design