There's an interactive online map of army barracks in Ireland. It's earlier than the time you asked about but I should think that many barracks on the map would still have been used in late 19thC.
Army Barracks of Eighteenth Century Ireland
https://barracks18c.ucd.ieIt's part of a project "Mapping State and Society in Eighteenth Century Ireland.
270 barracks active between 1690 and 1815 have been mapped. There's more detailed information + pictures about barracks in County Armagh. I clicked on "updates" but no mention as to details to be added for barracks in other counties.
The Irish history website
https://www.historyireland.com has an article about the Curragh Camp, opened 1855. Thousands of troops were stationed at it. There was a large resident population who made a living by servicing the camp, including a bunch of immoral ladies known as "wrens". The regular number of "wrens" was estimated at around 100 but was said to rise to 500 when the Curragh was full of troops. Put barracks into search box on this website to find articles about barracks in other places.
Googling army barracks in Ireland 1800-1900 brings up plenty of pictures.
Military History Society of Ireland may be worth a look.
There are more posts on RootsChat and other forums about army in Ireland.