I recall an article saying that a) We use rebar in concrete for tensile and shear strength, which massively decreases the amount of concrete you need but short

I recall an article saying that a) We use rebar in concrete for tensile and shear strength, which massively decreases the amount of concrete you need but shortens lifespan. b) Our concrete sets a lot faster. c) The specific mineral that the nature article is about, was already known. (I'm not sure if it was widely known.) (These are the main things I remember, anyway.)