Runway strength is certainly not an issue the runway is concrete PCN 61R/A/W/T whilst the loading isn't the highest it is Rigid (R) and its sub sructure is the strongest (A) also it's rated for maximum tyre pressure allowed (W) and has been evaluated by Technical evaluation (T).As a comparison Birmingham is PCN 63 F/B/W/T Manston is PCN 53 F/C/W/T. If I remember correctly before the 747 could operate the then Runway 28 was dug up (an asphalt runway) to strengthen the pavement to allow the 747 to taxy through Bravo to the apron.
The only problem I can see is where they would park the beast without disrupting other larger ac movements. If it used one of the airbridges then it would probably preclude ac taxying behind it.