Pretty minor. If they picked up the whole data center and soaked it in a large jug of 10% acetic acid for about nine months, the concrete would lose about 20% of its strength.

Not sure about the civil engineering side, but I assume there's enough safety factor in your average construction to account for 20% strength loss.

Not an engineer but vinegar (ascetic acid) at full strength applied early enough during curing could be a problem. If it's the watered down stuff for home use and the concrete was already partially cured it wouldn't do almost anything.