What is 5050 concrete mix. My buddy says he has a friend that lays concrete and that he uses 5050 concrete that does not need rebar in it. I need to lay a lot of concrete for a patio and sidewalk. Is this fine or will this create problems in the future not using an application with rebar.

No your buddy right that will be fine did mine 2 years ago and its OK

So how is 50/50 mix different that standard concrete needing rebar?

To be honest you do not really need rebar most house drive ways are built without it if you wanted you could just chicken wire. If you do not use rebar it will be easier to take up the patio in time but more resistant to cracks

Mike, call your local concret company and ask what they recommend and it will be their 6 bag mix. It has about 550 lbs of portland to the yard. Never heard of a 50/50 concrete so I think your buddy is passing along something that maybe someone else told him.

Never heard of 50/50 concrete either and I have been in the business for over 20 years. If you don't use rebar you can pour a fiber mesh concrete which is good but in my opinion nothing is as good as steel mesh or rebar.
Mike