In a reinforced concrete beam, what is the primary function of stirrups?

• A. Provide shear resistance and transfer transverse forces
• B. Increase axial compression
• C. Improve surface finish
• D. Reduce cement content

Answer: (A)

Stirrups provide transverse reinforcement that resists shear in a reinforced concrete beam. They bridge potential diagonal cracks by crossing the shear plane, helping to carry shear forces into the stirrups and surrounding concrete, and they keep the main reinforcement aligned and confined, which also improves ductility of the core.

This is why they’re essential for shear capacity and crack control. They don’t primarily increase axial compression, improve surface finish, or reduce cement content, so those options aren’t the governing function of stirrups.