colsie:
May i then ask what occurs with the composite aircraft when and if they are retired?
There is no difference: reusable materials are recycled, others are destroyed (incinerated).
This is nothing new, since already todays aircraft have considerable percentages of non-reusable materials. Think about the seat tissue, the cabine covers, but also heavy structurs like the vertical stabilizer of an A300 (of which the first ones are slowly being retired) are non-reusable (stabilizer: composite material).
You also have to forget the notion that composite aircraft are made of fibers/resin only. Modern heavy duty composites like on the 787 partly consist of light weight metals. They first have to be extracted from the composite and can then be recycled.
Dani