Perhaps not useful for your desire for exposed limestone but I used XYPEX admix in the concrete for my retaining wall hillside cut out and floor foundation. Works well.………
But then i started to worry about water coming through. Nice to see others in the process.
Xypex | Concrete Waterproofing using Crystalline Technology
For more than 50 years, Xypex has been providing Concrete Waterproofing products using Crystallization Technologies. Read more about our Concrete Coating Products.