Lori,
The main US fly ash brick manufacturer, Calstar, went out of business a few years ago and someone took over their production, but I don’t know if they are still making any brick. So you are going to find it hard to find any info on fly ash brick, except on a theoretical level. As for other masonry materials you can go to the appropriate associations to get data from them. For clay brick, go to the Brick Industry Association and check out their Technical Notes 48. For concrete block go to the National Concrete Masonry Association and check out TEK 6-9B. Both documents will give you a starting point.