What is Stirrup?

A stirrup is a closed loop of reinforcement bar that is used to hold the main reinforcement bars together in an RCC structure. In a column, the stirrups provide the lateral support to the main bars against buckling. When used in beams, a stirrup is termed as shear or transverse reinforcement since it withstands the shear force. Stirrups can be of various shapes depending on the design and shape of the load bearing member e.g. Circular, polygonal, a U-stirrup or a crosstie. However the most commonly used shape in normal construction is a rectangular or a square one.

Traditionally, in India, the stirrups are made manually at the construction site by the bar benders using rudimentary practices. In most cases, such stirrups do not comply with the prescribed standards. Beside dimensional inaccuracies, this can lead to improper locking of the ends thereby increasing the chances of failure during earthquakes. Stirrups of inferior quality act like "weak-links" in a RCC structure and can enhance the chances of collapse of a building under adverse conditions.