What is the ruling on building graves with cement blocks and placing a 10 cm layer of cement on them, and does this fall under the category of "plastering graves, which is forbidden," bearing in mind that the use of cement aims to protect the grave from erosion, animals, or exhumation?

The Sunnah regarding graves is that they should not be raised more than a handspan, due to the Prophet's (peace be upon him) prohibition of raising and plastering graves, and his command to level them. It is disliked to plaster graves or to use fired bricks and the like, except out of necessity. This can be avoided by deepening the grave and properly compacting the soil.