Tensile failure of a mild steel reinforcement bar


    mild steel
    12 mm diameter x 460 mm length
    65 kN
    45 mm

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

This video shows the behaviour of a mild steel reinforcing bar in tension. Steel such as this is no longer used very much in reinforced concrete. It is included here for you to compare the behaviour of mild steel with high-tensile steel.

The sample in this test is held between two jaws. The testing apparatus pulls the upper jaw upwards, causing the sample to stretch until it breaks.

Reinforcing steel is used in reinforced concrete elements to give these elements tensile strength.

At the end of the video a graph of vertical load versus vertical deflection shows how mild steel behaves under tension. You can download this data by following the link below.

The tensile behaviour of mild steel should be compared with the tensile behaviour of high-tensile steel reinforcement (see the video called ‘Reinforcement (high-tensile steel) – tensile failure’).

The test demonstrates:

  • The ductile properties of mild steel
  • The yield point, working hardening and ductile zones of a mild steel
  • The trade-off between increasing strength and reducing ductility

Download Data for this Test

Download the datasheet for this demonstration: