Experimental Study on Prestressing Force of Corroded Prestressed Concrete Steel Strands

This study presents the effect of corrosion of prestressed concrete (PC) strands on the prestressing force and the reduction mechanism of the uniaxial force. A total of 14 strands was tested by combining a rigid frame testing machine with an electrified accelerated corrosion device. The specimens were divided into two groups having prestressing levels of 70% and 50% of tensile strength of PC strands. The expected degree of corrosion of the specimens, which was defined by the mass loss, was calculated from controlled electric current and time. A rigid frame testing machine was used to sustain the tensile force of the PC strands, and the prestressing force and deformation of the strand were continuously measured during the corrosion test. The test results indicate that the prestressing force decreases with the increase of corrosion. After the corrosion tests, tensile loading tests were carried out on the specimens that did not rupture during the corrosion test. It was found that corrosion led to the deterioration of the tensile properties of the PC strands, and the ultimate tensile capacity of the corroded PC strand was related to the fracture condition.