I'm not sure what the problem is and what you are considering as lime concrete. If you are thinking that lime concrete is a material using hydraulic lime then it can work, depending on the usage. Many historic buildings have been constructed and have mortars using hydraulic lime... many have had problems because the hydraulic lime wasn't sufficient and have deteriorated.
As for the Bentonite soil, in the Winnipeg area, we have a highly plastic clay... not as plastic as some Bentonites, but the problem for our concrete is the high sulphate content and it is common to use type 50 or type 5 cement.
