I'm interested in building a garden wall from either concrete or rammed earth, or a mixture of the two, but I'm concerned about Michigan winters and the havoc they wreak on everything solid. It seems that all concrete steps I've ever seen around here are either quite new or in the process of disintegration. I would consider anything that can't last 100 years to be a failure.
I've been unable to find any good information online about this, and even asking a friend who is a builder didn't turn up any good info. (It seems that all residential buildings around here are built from wood, primarily.) It's easy to find info about the frost line, but not about the actual longevity of the concrete (or rammed earth) structure. How would I go about getting information on how to build/pour a wall so that it can last a century or more?
Also, could I expect rammed earth to be more or less resilient to cracking? (Would the clay involved make it a bit more flexible than straight concrete?)