Innovative approach for the protection of recycled concrete by biogenic silica biodeposition

•Diatom biodeposition is proposed as a surface treatment for recycled concrete to increase concrete durability.•The waterproofing effect of biogenic silica on recycled concrete was tested by several durability parameters.•The characteristic appearance of diatom biodeposition on recycled concrete was observed by SEM.•Biodeposition increases the water-resistance of recycled concrete by lowering its water absorption capacity.