Can I concrete over concrete???

We are in the midst of preparing a base for our new larger shed, part of the base will be an old concrete path, but this needs to be rasied in height.
Do i need to break the path up to lay more concrete over the top, or will it be ok to lay straight on top? Or could i just 'score' the top of the old path to help the new concrete stick?
thank you for your help.

if the UK suffered extremely cold and prolonged winters (like Canada, Russia etc.) then i would say no. here in the UK - yes.

clean all the rubbish off the top, wet it prior to laying then fill ya boots.