Transport of Chloride Ions Evaluation through Modulated Concrete Microstructures

Abstract

It is known that the properties of concrete, including the transport of moisture, depend on its microstructure, which can be modulated by chemical and mineral additives, termed as admixtures. In the previous study, the effect of admixtures, such as glycerol as a nanoviscosity modifier, was evaluated indirectly by measuring the corrosion rate of reinforcement steel. However, it was found that this method (corrosion) could be biased due to the effects of admixtures on corrosion inhibition per se. Therefore, there was a need to evaluate the concrete permeability by direct transport through its matrix. This was done in a new experimental design, which allows direct measurement of chloride concentration change with time. A concrete with particular admixture, and of disks geometry, separates two compartments. A ponding compartment serves as a supplier of chloride ions, which upon transport through the concrete matrix are received by a pure water compartment. Chloride concentration in initially pure water compartment is measured with time using ion chromatography.