I would like to try to suck the clog out, if that's the problem...but I
don't have access to the other end, it goes into my concrete floor.

At this point, I think I will try cutting the pipe just above the
floor, and making sure it's clear until that point. If so, I'll see if
I can fish a snake down into the floor, and see if its clogged down
there. If it isn't -- or if I can't tell -- how would I go about
creating a proper condensate trap? Should it be a closed loop, to
create a vacuum? If not, how would the water get around the turns and
past the trap in the PVC?

Thanks again for everyones help!