hey latex-

take a look at my 'pro shaders" #1 product; you may find a couple of the materials in there do just this.  the motherlode and adobe shaders are both designed to tune up into a variety of super distressed materials.  blood orange, with some colour tweaks (or just add a concrete image into hte diffuse channel) will also serve you well.

i do also have a very nice cement specific shader coming out in my next pack....when i am home from travels mid-december, i will be glad to share that one w/ you as a freebie!

isn't fallout great!?

s/.