What is Thermo-electric prestressing
We know that, stretched tendons are used in prestressed concrete. Stretching of tendons may be accomplished by using jacks or by other means. Thermo-electric prestressing is just another method of stretching the tendon wiers. We know that if we increase the temperature of a metal, it expands. As the name suggests, in Thermo-electric prestressing, temperature of tendon wires is increased by passing electric current for a short duration. This temperature increase, taking place within 3-5 minutes, may be of an order of 300-400°C. The bars, which may undergo an expansion of about 0.4-0.5% in length, try to shorten at cooling butare checked by fixed anchors at the two ends.