'Nother question.
Since we are on the subject: I have a 5'x6' entry/stoop/alcove that leads to my front door; not a porch, but it is concrete and has 2 concrete steps leading up to it. I was thinking if I used clear silicone I could cover that floor and step surface with the glass, a small section at a time. If I did that there would be nothing to seal the glass in because even a thin layer of concrete wouldn't likely adhere to the silicone, would it? It would leave the surface covered in rough glass.
Can you cover old concrete with new? Unlikely, I guess.