Welp, a two handed sword broke after using it too much, and thereafter a new item appears called "broken weapon".
Is there something I can do with a "broken weapon"?
Every iron o steel weapon will break because of the iron crisis if not enchanted or if you are not using any mod.
You can discard it, the broken weapon can't be reforged, recycled or sold and has no value in the game at this point, except for item collectors (in un-modded Baldur's Gate anyway). http://baldursgate.wikia.com/wiki/Broken_Weapon