Determination of the chloride diffusion coefficient in blended cement mortars

Literature shows that the RCM test development and experience concerns only Ordinary Portland cement. Therefore, a validation of this test method is needed for other types of binders. This study analyzes the application of RCM test for mortars prepared with different binders: Ordinary Portland cement (OPC), ground granulated blast – furnace slag (GGBS), fly ash (FA) and silica fume (SF). The silver nitrate colourimetric method is applied here to assess of the chloride penetration depth, which is subsequently used for the calculation of the chloride diffusion coefficient DRCM according to NT Build 492. A comparison is given between the results of the total chloride concentration profiles measured in mortar after the RCM test and results indirectly obtained from extended chloride transport model. The performed analyses show that the accuracy of AgNO3 colourimetric method is sufficient for the determination of the DRCM for different type of binders.