Doors have durability

I was playing on my friend's realm while I was destroying a block using a door. After I destroyed it,the door showed a durability bar. I don't know if this also happens in 0.15.1 build 1,because I can't sign in to my Xbox Live Account which is kind a bit annoying. If this issue is a duplicate,then I'm sorry,I don't have the time to search. Please fix this and I will really appreciate your work.