What is the purpose of a plain bar in reinforced concrete?

The purpose of a plain bar in reinforced concrete primarily revolves around its function as a connector rather than a support element. When using plain bars, they are often incorporated to facilitate connections between adjacent reinforced concrete members. This is crucial in ensuring structural integrity, particularly in scenarios where different parts of a structure need to interact with each other, such as at joints or intersections.

Plain bars can effectively allow for slip, which is the relative movement between components. This characteristic can be beneficial in accommodating thermal expansion, shrinkage, and other movements that occur in concrete structures due to environmental changes.

While plain bars may have some bonding properties with concrete, they do not possess the same deformed surface features as deformed bars, which are specifically designed to enhance bonding and mechanical interlock with the concrete. Moreover, plain bars do not provide tension support in the same manner that reinforced bars are intended to do. Reinforced concrete relies on appropriately designed reinforcement to handle tensile forces effectively, thereby ensuring the overall durability and safety of the structural system.