Need help with broken partition

Hello. Today i have tried to install windows 8.1 via bootcamp, after bootcamp repartitioned 80GB, mac restarted and appeared flashing folder with question mark. Couldn't start my mba even with macintosh hd startup, only helped removing bootcamp partition via recovery disk utility. Now mac can start but faced up with another issue- seems that I have lost those 80GB and can't remove that partition via bootcamp or disk utility. At disk utility it is shown as free space partition and can't format to any other. Repairing disk doesn't help.
What can I do? I have timemachine backup, however tried to reinstall os x, but ssd is shown without that 80GB
Please help, tried everything and searched everywhere :/