Conkeldurr's English name might be a play on the internet Meme/Phrase "Hurr, Durr, Derp, Err" explaining its facial expression.
Even though it evolves from Gurdurr, it makes more sense to be the other way around as metal is stronger then concrete.
Conkeldurr appears to be based on a construction worker. It also closely resembles a buff clown or "muscleman" from a carnival sideshow, giving it a less serious appearance (due to its large red nose and clown-like face and colors). Conkeldurr seems to sport a grey goatee on its chin as well as some sort of top-knot, giving off the impression of an old martial arts master.
Conkeldurr's English name is derived from "concrete" and "elder".