Greenham Common had the runways removed for gravel extraction
In actual fact, 1000's of tonnes of Greenham concrete was used in the construction of the Newbury bypass (A34).
Greenham does look like a missed opportunity on the face of it, but one not immediately obvious obstruction to its development as a civilian airfield might be the large "weapons factory" that lies at approx 5 miles under the extended centreline for the former westerly-facing runway.
(have a look on Google Earth)