Evaluation of Chloride Intrusion along Concrete–Grout Interfaces for Post-Tensioned Concrete Durability

Abstract

A pour-back is a critical component of a post-tensioned concrete system, affecting its durability by protecting anchorages and vents from corrosion. However, the material interface between the grout pour-back and the concrete member may serve as an accelerated pathway for chloride ion intrusion and may lead to premature corrosion of post-tensioning components. This study evaluates the vulnerability of concrete–grout interfaces through two experimental protocols: a novel electrical migration test and the standard electrical resistivity test. The results are used to predict the service life of pour-back systems using a concrete life-cycle assessment model. This research serves as a first step toward defining the chloride permeability of concrete–grout interfaces.