There's one here in Ireland working away or there was anyway mixing up stuff for bricks and chimney pots. Big old lump of a Massey powering it. I must ask the man that told me about it of it's still going. I'd imagine mixing concrete wouldn't be that hard on it so long as it's not let get to dry and stiff in the wagon.I've heard of Keenans being used for mixing concrete, and apparently quite successfully. Crack on.