is a method of strengthening concrete prior to its installation.
The concrete that is pre-ressed makes use of Rebar to shield it from destruction by tensile forces. Concrete is a great material for handling compressive force. The best example of compression force is when you place your foot on the soda bottle and crush it to flat. Tensile force, also known as tensile strength will cause an object to break apart.
When you construct concrete structures, you can expect to have two types of force that are acting on concrete. For instance, let’s consider an example of a bridge. When a heavy load moves over the bridge, the upper part of the bridge stretches when compressed and stays up. The bottom part of the bridge gets pulled apart. The bottom will form cracks that will fail and fall apart without rebar.
Concrete is set up through pre-stressed techniques that introduce the rebar in concrete. Rebar is stretched by using specially-designed machines. After the concrete has been put to the ground, the bars puts just the right amount of stress on the concrete in order to keep it together against tensile force.
The full details can be found in the video below.