Concrete spacer blocks are the small concrete parts that are used to ensure the position of reinforcement (i.e. steel) in the right place with a specified concrete cover. In RCC structures like slab, beam, column, footing, etc. concrete cover is provided to maintain the durability of the structure. Concrete Cover is the minimum distance between the surface of embedded reinforcement (i.e. steel) and the outer surface of the concrete. Concrete cover varies from 15mm to 50mm for different structural members.
e.g. SH65/75 used for 65/75 mm cover for slab and beam
e.g. SB300 used for heavy structures