This feature has been labeled as
deprecated. The recommended replacement is:
surface=concrete.
The reason is documented in
Deprecated features. You are still free to continue to use or interpret this tag as you see fit since OpenStreetMap does not have “banned features”.
Under no circumstances should you (semi-)automatically change “deprecated” tags to something else in the database on a large scale without conforming to the
automated edits code of conduct. Any such change will be reverted.
Often used, by mistake, instead of surface=concrete
See https://community.openstreetmap.org/t/mysterious-surface-cement/5158 for discussion
See also Mechanical Edits/Mateusz Konieczny - bot account/migrate surface=cement to surface=concrete on USA roads and paths