Non-destructive methods for measuring chloride ingress into concrete: State-of-the-art and future challenges

Chloride ingress is one of the major causes of reinforced concrete (RC) deterioration. Free chloride induces the corrosion of rebars, reducing the material strength, and therefore, the structural behavior. This paper highlights the importance of chloride content measuring, and also summarizes the state of the art of non-destructive and in situ techniques for measuring chloride content into concrete structures. These techniques have been developed over the past twenty years, and they have been shown as good alternatives in durability field. They are based on three methods: electrical resistivity (ER), ion selective electrode (ISE) and optical fiber sensors (OFS).