Produced with funding from CONSTRUCT and filmed at Imperial College London.

This video shows the behaviour of a reinforced concrete column in compression. Such columns are one of the most common structural elements used in concrete construction.

The column is supported on either end using spherical bearings which allow the ends of the column to rotate. The testing machine applies an axial compressive load to the column. Very little movement is seen as the load increases. The column fails suddenly when the load reaches approximately four tonnes.

At the end of the video, a graph of load on the column versus vertical compression is shown to illustrate the behaviour of this column under axial loading. This test demonstrates:

• The axial shortening of a column in compression
• The sudden failure mechanism of a stocky beam in compression
• How a pin support allows the end of column to rotate

The way that a column reacts when a load causes it to compress depends in part on the geometry of the column. This column is displays behaviour typical of a stocky column in compression. A slender column will behave differently.

The behaviour of the column also depends on the way that the column is restrained at either end. This column is pin-ended – the spherical bearings at either end allow the column to rotate freely. If the rotation at either end is restrained, then the column will behave differently.

Compare the behaviour of this column with the behaviour of a concrete cube or concrete cylinder in compression.

Download Data for this Test

• Download the datasheet for this demonstration (PDF, 51KB)