Yep, just a bit of weathering, cracks and staining. But think about it first - where is the area, parking, servicing etc. What's the surface, concrete, stone, tarmac etc.? Weather- wet, dry and hot and so on? Which part of the world etc? All of these things will effect what you wish to achieve. I normally use mounting card for the 'hard' areas, such as dispersals, taxi tracks etc., and but-joint to simulate, for example, concrete slabs. This can then be painted and textured according to requirements. I think this is covered (in part at least) in the Diorama Guide. This way, you can add grass to the cracks, if it would be present on the 'real thing', or simulate the actual gaps, or add the tar sealer often used between slabs.
The thing to do is study as many photos as possible of actual airfields, relevant to the subjetc being modelled. I've seen many models on bases that look far too 'clinical' and precise, and often of the wrong type for the particular aircraft sitting on them! When it comes to location, it doesn't really work to build an accurate replica of the apron at a Florida airport, if the subject is supposed to be a bleak USAAF base in East Anglia, UK, in the depth of Autumn! World War two subjects can vary a heck of a lot, especially if the airfiled was a temporary base, and even permanent fields were relatively new, and hurriedly constructed, so there was often rubble, mud, eroded paths etc etc. But, on the other hand, an F16 would normally be standing on a very tidy, relatively clean and smooth apron, with the surroundings equally neat and tidy.
Building a base is the same as building any other model - it's a model in its own right, and should never be treated as an afterthought or last-minute addition. A poor base can ruin the display of an excellent model.