Simplified chloride ingress quantification using SEM-EDS and the square root law in cement pastes

The performance of cementitious systems against chloride ingress is generally characterized using a four-step process: samples preparation, chloride exposure (with or without acceleration), penetration measurements and diffusion modelization. However, parameters and tools can be further refined. Variations in exposure conditions are still debated (frequency of solution renewal, pH adjustments with KOH). Profiles are typically obtained using titration method and analyzed using the apparent diffusion coefficient approach, whose complexity and limited precision leave room for improvement. This study proposes a simplified and complete protocol for chloride ingress quantification by assessing exposure conditions using SEM-EDS and the square-root law. The results validate the ability of SEM-EDS and the square root law to quantitatively and precisely characterize chloride ingress behavior and show that the typical renewal times for the exposure solution did not affect chloride ingress. Overall, this study provides guidelines for the efficient quantification of chloride ingress behaviour in cementitious systems.