I would like to start biking to work which is about 9 miles one way. There is a shower facility at work along with an indoor room to lock and store the bike during the day. Essentially, the bike storage room has a basic outdoor style bike rack that everybody uses. My dilemma is I own a Trek Domane 5.2 and I'm not sure I trust storing my bike there without getting abused with nicks, bumps and scratches. Not that anybody would do this on purpose but accidents happen.

Would I be better off buying a used bike for the commuter and keeping my Trek for my training rides? What have others done in a similar situation?