Modification and Verification of the RCM Test for Concrete with Alternative Binders

Abstract

Chloride‐induced reinforcement corrosion is a major durability concern in infrastructure building. Assessing the chloride resistance requires accurate, reproducible and efficient testing methods. The Rapid Chloride Migration (RCM) test is a well‐established method to assess the chloride migration coefficient. However, with the increase of alternative binder concrete, the properties of the materials are changing, making it necessary to re‐evaluate and optimise existing test methods.

This study builds on previous efforts to enhance such methods, focusing on the conversion of the Specific Charge Flow Rate (SCFR) and the Specific Electrolytic Resistance (R _spec ) into a calculated chloride migration coefficient (D _RCM,calc ). Over 90 concrete specimens were investigated, incorporating CEM II and CEM III cements as well as various alternative binders. Additionally, voltage losses in the test setup were determined to verify the commonly assumed voltage correction of 2 V in existing guidelines.

Comparison with measured DRCM values indicates that the conversion of electrical parameters is generally feasible. Low standard deviations can be achieved. However, prediction accuracy decreases for migration coefficients exceeding 5.0 × 10 ^–12 m ² /s.