Determination of the chloride diffusion coefficient in mortars with supplementary cementitious materials

The Rapid Chloride Migration (RCM) test, described in the guideline NT Build 492, is one of the most commonly applied accelerated test methods in which chlorides penetrate the concrete at high rates due to the applied electrical field. The output result of the test is the chloride diffusion coefficient DRCM. Literature shows that the RCM test development and experience concerns only ordinary Portland cement. Therefore, a validation of this test method is needed also for other types of binders. This study analyzes the application of the RCM test on mortars prepared with different binder blends: ordinary Portland cement (OPC), ground granulated blast – furnace slag (GGBS), fly ash (FA) and silica fume (SF). The diffusion coefficients are obtained by two approaches: the basic RCM test model and the extended model which considers non-linear chloride binding in non-equilibrium. The analyses presented in this study show that the RCM test can be used for the determination of chloride diffusion coefficient in mortars with supplementary cementitious materials, and the accuracy of AgNO3 colourimetric method is sufficient for the determination of the chloride penetration front in these mortars

Determination of the chloride diffusion coefficient in mortars with supplementary cementitious materials

The Rapid Chloride Migration (RCM) test, described in the guideline NT Build 492, is one of the most commonly applied accelerated test methods in which chlorides penetrate the concrete at high rates due to the applied electrical field. The output result of the test is the chloride diffusion coefficient DRCM. Literature shows that the RCM test development and experience concerns only ordinary Portland cement. Therefore, a validation of this test method is needed also for other types of binders. This study analyzes the application of the RCM test on mortars prepared with different binder blends: ordinary Portland cement (OPC), ground granulated blast – furnace slag (GGBS), fly ash (FA) and silica fume (SF). The diffusion coefficients are obtained by two approaches: the basic RCM test model and the extended model which considers non-linear chloride binding in non-equilibrium. The analyses presented in this study show that the RCM test can be used for the determination of chloride diffusion coefficient in mortars with supplementary cementitious materials, and the accuracy of AgNO3 colourimetric method is sufficient for the determination of the chloride penetration front in these mortars

Determination of the chloride diffusion coefficient in blended cement mortars

The rapid chloride migration test (RCM) is a commonly used accelerated test for the determination of the chloride diffusion coefficient in concrete. Nevertheless, the initial development and further experience with the RCM test concern mainly the ordinary Portland cement system. Therefore, the objective of this work is to analyse the application of this test method for other types of binders, by performing and analysing the RCM test results for mortars prepared with additions of supplementary cementitious materials. A comparison is given between the total chloride concentration profiles measured in concrete after the RCM test and the colourimetric test results. The presented results show that the accuracy of the silver nitrate colourimetric technique is sufficient for the determination of the chloride penetration front and that the RCM test is a suitable method also for the determination of chloride diffusion coefficient in mortars with blended cements