What is considered acceptable for supporting reinforcing steel?

In the context of supporting reinforcing steel during concrete placement, it is crucial to use materials that can maintain the integrity and position of the rebar without compromising the quality of the concrete. Typically, acceptable supports for reinforcing steel include specific materials designed for this purpose, such as steel chairs, plastic supports, or concrete spacers, rather than common construction materials like wood, rock, or brick.

Using wood as a support for rebar can lead to issues such as degradation and deformation, especially if exposed to moisture. Similarly, rocks may not provide a stable or uniform support, and bricks do not offer the necessary precision or reliability required for proper placement. Each of these materials could potentially lead to misalignment of the reinforcement, which would negatively affect the structural integrity of the finished concrete element.

Thus, the option stating "None of the above" indicates that the choices provided do not meet industry standards for supporting reinforcing steel. This emphasizes the importance of using appropriate materials specifically designed for this task to ensure the safety and durability of the concrete structure.