The Use of Stirrups

Beam—The Most Classic Application:

The primary function of stirrups in a beam is to resist shear forces and constrain the longitudinal reinforcing bars to prevent lateral deformation. They also enhance the beam’s shear resistance. In particular, shear forces are greater at the beam ends and near the supports; therefore, construction standards require a denser arrangement of stirrups in these areas.

Reinforcement Densification Zone

Column — Stirrups

The primary function of column stirrups is to constrain the concrete, improve the column’s ductility, and prevent deformation of the column’s longitudinal reinforcement.

Column Stirrup Installation Process

Beam-Column Joint

A beam-column joint is the area within a reinforced concrete frame where:

the beam and column are connected to each other and transfer bending moments, shear forces, and axial forces.

Inside the joint, there are actually column longitudinal bars, beam longitudinal bars, joint transverse reinforcement, and a concrete core.

Beam-to-column joints are subjected to highly complex forces under normal loads and, in particular, under seismic loads.

Beams transfer bending moments and shear forces to columns, which in turn transfer the loads downward.

Under seismic loads, plastic hinges may form at both ends of the beam, causing the beam’s longitudinal reinforcing bars to experience significant tensile and compressive forces, which are ultimately transmitted through the joint.

Stirrups serve not only as “shear reinforcement” but also as confinement reinforcement.

Beam-to-Column Joint Drawings

Names of Stirrup Components:

1. Beam Stirrups

2. Column Ties

3. Foundation Stirrups

4. Seismic Stirrups

5. Bridge Stirrups

6. Precast Concrete Stirrups

7. Shear Wall Boundary Reinforcement

8. Coupling Beam Stirrups

9. Custom-Bent Stirrups

10. CNC / Machine-Bent Stirrups