sprues are great for using as building girders/supports as pointed out! to give them that extra bit of realisim, take a pin vice and drill a hole into the top end, then jam a paper clip into it! (obviously, you'll need the superglue here!) once it's dry, just clip off the end and voila! part of a steel re-inforcement rod sticking out!
this is great for using up the elbow's of used paper clips... the natural curve can also help you model the angle of the original blast!
cheers!