I'll have to dig out an archaeologist but I don't thank that is quite right. I'm a Civ Eng graduate BTW. Romans - conc - yes. Inventors - maybe but probably

I'll have to dig out an archaeologist but I don't thank that is quite right. I'm a Civ Eng graduate BTW. Romans - conc - yes. Inventors - maybe but probably not (see below) Medieval period - conc - probably available and probably used Conc is a funny old beast. Basically, it is a chemical reaction between its ingredients and not a drying out and setting thing. That's why it will set underwater or if you pour too much in one go, it will set itself on fire - exothermic reaction. I suspect with no evidence whatsoever that someone will have noticed how mixing water with some types of earthly deposits etc etc. Look at "cob" which is straw and mud and water and some pretty interesting admixtures - starting with wee (horse and human.) My aunt and uncle's last place had 1620 written on the wall near the entrance - so a bit modern for these parts. It is cob and thatch with a few sticks thrown in. I suspect that conc of some sort is ubiquitous throughout history and has simply not been noticed by us modern lot. However it does generally require processing of some of the raw ingredients so perhaps I'm off course.