[Cob] lime mortar

[Bob Smolen]

Last fall, I started gathering old foundation rocks for my cob project. At two sites,only the 8ft stone stem wall was standing where a barn once stood. It was probably 110 years or older. I was able to knock down the wall by pushing on a leaning section. I did not really look at the foundation but the owners commented that the wall came down easy because of the mortar used in the old days. I believe he said it lacked cement which means it must have been lime mortar. Is this an indictment of a non cement mortar? I know the wall was subjected to years of weather unprotected so  maybe deterioration should be expected. On the other hand, I dont think the weather would have affected cement mortar. ( I did not notice the foundation wall. It may have heaved after the roof of the barn was off allowing moisture under the footer causing frost heave).
Is lime mortar as good or close to as good as cement mortar for buiding stone walls?
Thanks,
Bob