A simplified stress-strain relationship for the mechanical behavior of corroded prestressing strands: The SCPS-model

This article presents a simplified stress-strain relationship for the definition of the mechanical behavior of prestressing strands subjected to chloride-induced corrosion, named SCPS-model (Simplified Model for Corroded Prestressing Strands). The constitutive law adopts the equivalent spring model, that reproduces the overall behavior of a corroded strand by summing the contributions of each wire, assumed as a spring working in parallel to the others. The SCPS-model is designed for the application in the daily engineering practice; to this aim, it is based on a single input parameter that is the maximum penetration depth of the most corroded wire. Following a detailed description of the model formulation and parameters, the article shows the validation of the stress-strain relationship through several comparisons with experimental tensile test outcomes coming from scientific literature. Finally, a statistical analysis of the dimensionless ratio of experimental and analytical results in terms of ultimate corroded strength and strain is carried out to demonstrate the effectiveness of the SCPS-model. Concluding, the accurate and safe side prediction of the residual mechanical behavior of corroded prestressing strands is proposed using the SCPS-model.