Which type of reinforcement is primarily used to address shear forces?

The primary function of stirrups in reinforced concrete structures is to resist shear forces. These are U-shaped or closed-loop bars placed perpendicularly to the main longitudinal reinforcement within a beam or column. Stirrups provide lateral support and help confine the concrete, improving its ability to withstand shear stresses that can cause cracking or failure in the material. When shear forces are present, the stirrups act to hold the concrete in place, preventing it from sliding and ensuring the integrity of the structural element.

Longitudinal bars are essential for handling tensile forces and bending moments, while fibers can improve tensile capacity and toughness without significantly addressing shear directly. Epoxy-coated rebar is primarily used to resist corrosion rather than specifically address shear. Therefore, stirrups are the correct choice in the context of addressing shear forces in reinforced concrete elements.