The use of materials such as rock, brick, or wood to support reinforcing steel is not considered acceptable in concrete construction due to several reasons related to safety, structural integrity, and durability.
Reinforcing steel, or rebar, must be accurately positioned and securely supported to ensure that it maintains the correct placement within the concrete. This is critical for the rebar to perform its function of providing tensile strength, which is essential for the structural performance of concrete once cured.
Using non-standard materials like rock, brick, or wood can introduce variables that compromise the stability and alignment of the rebar. These materials are not designed to uniformly support the weight and positioning of the steel, and they can be subject to degradation, movement, or collapse under load conditions. Additionally, these materials may not provide the necessary support during the pouring and curing processes required for concrete, increasing the risk of defects and failures in the final structure.
Industry standards promote the use of specific support systems, such as rebar chairs, spacers, or other engineered materials, to ensure that reinforcing steel is supported properly and remains in place during and after the concrete pouring process. Adhering to these standards is essential for ensuring the safety and longevity of the structure being constructed.