Correct me if I'm wrong, but wouldn't it have to be two sentences with this punctuation? As in, it should be: AJ came to on the cold ground. Her mouth was full of blood and sand. I think if you omit the "was" it would work.
Hmm, I don't know. God it's been too long since school and too much time on the Internet (where grammar is treated like a plague). But, I prefer "AJ came to on the cold ground, her mouth full of blood and sand". And, even more, "AJ came to on the cold ground, tasting blood and sand". There's an alliteration of "came" and "cold" as well as a parallel structure of "came to" and "cold ground". The first clause has a pentameter with the acccent on the first syllable of each meter. This continues halfway through the second clause, but breaks at 'blood' and, therefore, brings attention to "blood and sand" - where we want attention to be brought.
mbinks89 is correct. In the example with the 'was' still included, you now have two complete independent clauses. A period must separate them. Lose the 'was' and you now have an independent clause followed by a dependent clause. A comma should separate them.
~~~~~ AJ Connor awoken feeling dirt scuffle around her face on the ground, as she started to cough blood...
I can't say which is more correct grammatically but I think I would break it up a bit more. Having it gently broken up by commas makes it seem like she is rising from a slumber rather than a soldier trying to be alert for battle. I think - but that is my opinion and I am not an editor. AJ came to. She was on the ground, cold dirt on her face, her mouth filled with the taste of sand and blood.