Indented PC Wire

 The pre-stressed steel wire is tensioned approx. 70 to 80% of the minimum specified breaking load of steel wire prior to casting of concrete. After initial setting of concrete, the pre-tensioned steel wire is released and the stress in the wire is induced in the concrete. This induced compressive stress will neutralize the tensile stress caused by the acting loads on the concrete member. In the case of pre-tensioning, it is important that adequate bond is created between the steel wire and concrete in order to transfer the desired compressive force from the steel wire to the concrete.