I believe there is a few topics that might be getting overlooked. One thing you may want to consider is the specifics of the tree. Lumping it into the genus of oaks (Quercus) will not be beneficial to your decision making in regards to the health of the tree in the future. Some oaks can be very adaptive to differing soil conditions such as wet (xeric) dry (mesic) and some oaks grow stronger and healthier in clays rather than sands and vice versa. For example live oak (Quercus virginiana), which i believe is what you have pictured, is an extremely adaptive species of oak that can grow in a wide variety of sites. It is common in dry sandy woods and it can be found in moist deciduous forests of riparian hammocks or flatwoods (which I believe is more common in your area, but I am not an expert in soils or the forests in your area). Live oak is also found along roadsides and on borders of salt marshes of the Coastal Plain (all this comes from a book Native Trees of the Southeast). What this means is all these locations are extremely oxygen deficient making the tree a common "street tree" planted along roads, parking lots, and sidewalks where oxygen is also lacking. In conclusion, although ATH is correct in regards to root depth and oxygen, a tree like live oak, so adapted over time to life around water, it isn't really a needy tree in regards to oxygen. I think your best bet is to follow a mixture of the local Fireaxman's and ATH's advice. Wait a year or two (which i know is hard to do because you are the one who has to look at it everyday) and observe the tree's health. Possibly consider taking a concrete saw to the concrete surrounding the tree creating a 2"- 4" gap (should be sufficient) at the lowest elevation allowing the water to drain from the base of the tree and disperse into the surrounding grass (probably bermuda for your area). The grass should be very good at taking in the moisture effectively because it calls for 1" to 1 1/2" of moisture a week. Treat mosquitoes as needed if larvae are present. If larvae isn't present, I wouldn't worry to much about it because of the fact you live in Louisiana and they will be in the area no matter what you try. Finally, periodic observation for a time you're willing to deal with and proper drainage should be all you need. Beautiful tree, I hope she lives a long good life.