Whenever I use him, I wind up unkillable/tanky but I don't like, hurt anyone. I'm like a friendly giant or something.
If you don't build a single damage item, then yeah, you won't do squat. His ult gives him a lot of tankyness, so he can afford to get two good offensive items and 3 defensive ones. Bork feels mandatory, and of course, Triforce is amazing cause of the 2 second bite. Pair that up with Randuins, Vysage and like Sunfire/Locket and boots of choice.