Non-Destructive Measurement of Chloride Profiles in Cementitious Materials Using NMR

Abstract

In order to measure non-destructively the ³⁵Cl in cementitious materials a special NMR setup was developed. Besides ³⁵Cl also quasi-simultaneously both ²³Na and ¹H can be measured. This setup is built around a 4.7 T wide bore superconducting magnet. The present results show that using this setup we can measure non-destructively the ³⁵Cl, ²³Na and ¹H in ordinary Portland cement samples. Using the present setup ³⁵Cl, ²³Na and ¹H profiles can be measured over a longer period of time, hence giving for example the possibility to look at the dynamic binding process of ³⁵Cl and ²³Na during hydration, as is demonstrated. Moreover, the measurement time with the present setup gives the possibility to look at the dynamics processes like, for example, the NaCl solution absorption as is demonstrated, showing NMR can be used for non-destructive evaluation.