Equivalent material model of corroded prestressing steel strand

Abstract

One of the main load resisting elements in prestressed concrete bridges is prestressing steel. Corrosion of the prestressing steel is generally protected by grouting and duct. Even though the strand is crucial, it is difficult to visually inspect the corrosion. In this paper, corrosion of the strand is classified into three types according to observation of corroded strands from existing bridges. Equations for section loss of the corroded strand were suggested. Mechanical properties of the corroded strand such as strength and ductility were estimated by tensile test. Finite element analysis on the corroded wire and the proposed spring model provided equivalent stress-strain models for corroded prestressing steel. The suggested models were verified by the tensile tests and can be utilised for the analysis of prestressed concrete members with corroded strands.