Has anyone ever heard of this? I have this one span table. I'm also looking for information on precast tongue and groove concrete plank. Would they have put any mesh in there or would it be plain concrete?
It looks like precast roof panels, I saw it once during a roof remodelling project for a water treatment plant. It stayed well, but the foam insulation and water proofing were deteriorated. vandede427 are correct, it was produced around 70's.
It may be a residential system, many attempts have been made to come up with lightweight flooring systems. Try ACI?. Would be interested to see what turns up.