# Effective Medium approximation of wet asphalt

So I'm trying to model the effects of wet and dry road surfaces for mm wave communication. My first attempt was to model the road as dry asphalt covered with a thin layer of water, but I'm not sure this is accurate enough since the water would be seeping into the asphalt in reality.

Is the Maxwell-Garnett equation for mixing dielectrics applicable here? I saw that the ITU-R recommendation on the surface of the earth used it to approximate the permittivity of wet ice, but I'm wondering if there's any reasons it shouldn't be used here.

• So, you're trying to communicate between two devices exclusively along the wet surface of an asphalt covered road without having some form of "air" connection? That's how it reads. – Andy aka Jun 12 at 15:20
• Andy aka, sorry maybe I wasn't very clear. The system I'm modeling is two antennas with line of sight sitting several meters above the road, I'm most interested in modeling the multi-path effects though, so I need to accurately represent the road surface below the antennas – user195951 Jun 12 at 15:24
• water would be seeping into the asphalt ... are you really sure about that? – jsotola Jun 12 at 19:47
• Jsotola, I really wasn't sure at all. If that doesn't happen in reality then I guess modeling it as a layer of water on top should be good enough – user195951 Jun 12 at 20:03