Absolutley add shavings. lime is a good base but not for laying down in. It will pack which is good for your stalls. But even with scant shavings, the horses will wear sores in their legs from laying down
Lime works great to help reduce odors... but it needs something on top of it.... Straw or sawdust/shavings, The best I ever saw was rubber mats on a 6 inch base of lime with straw over everything, but you need to keep the stalls clean... We cleaned no less than twice a day.