Stone Arch Viaduct / Bridge

[Charlie B]

Here is an article about making molds and building a stone arch bridge. http://www.gatewaynmra.org/2010/casting-...h-viaduct/ Dr Wayne swears by Durobond for castings and I heartily agree, though it gets very hard and then is hard to work with. available at any builders supply stores and in 3 setting times 20, 45, and 90 minutes  https://www.google.com/shopping/product/...lsrc:aw.ds
I really admire the research you have done on this and I do look forward to seeing the project when it is completed. 
Charlie