It appears that your concrete is freeze spalling. I would find a good repair mortar then waterproof the entire surface with a good sealer.
Any idea what that would cost? Probably 30ft by 40ft
Ardex products will have a product to repair any concrete surface with the correct surface preparation, used in commercial and industrial applications..
https://www.youtube.com/watch?v=wg7x5L0EAg0
Ardex is a great product however if the concrete that your covering is rotting from the inside out ( there can be a number of reasons-poor mix, water to cement ratio,air entrainment too much or not enough) then any overlay whether cementious,synthetic,acrylic will eventually fail.I think asphalt is the best option here.....a lot of times these types of overlays are not cost effective either..
Inside out? I would be more concerned about the moisture in the subgrade being drawn up into the concrete...