I'm having the exact same issue, premier cc gets to 80% on export and crashes. If you find a solution please let me know, if I find one I'll do the same .
What are you editing, and do you have any large pictures in your project?
I found a solution to export an hour long doc that worked with Premier CC,
File > Project Settings > General > Renderer
The Renderer is set to default as: Mercury Playback Engine GPU Acceleration (Open CL)
Change this to: Mercury Playback Engine Software Only
After weeks of exports failing at 80% changing this setting worked and it spit my MPEG2 file out in no time.
Hope this helps