Airfield apron textures

Hi folks.I've been installing new runway and concrete textures and notice that the concrete is only for taxiways. The rest of the apron areas are still that smudgy browny grey effect.Is there a replacement texture for that or is there a way to extend the new concrete texture to take in the rest of the aprons.Can I replace the apron texture bmp ( once I find it ) with the new concrete one? Or is that too simple?Thanks