Producing less corn rather than subsidizing it is the better way to go.

This just seems like another fake-green boondoggle, similar to ethanol.

Unclear on that first point. The authors claim 26 MPa for CoRncrete, which is about the same as the higher end of the range of concrete (~28 MPa) but much cheaper. On the other hand, it sounds like the paper's saying it's also much less durable.