Investigating the effects of testing protocol factors on chloride binding capacity in cementitious materials

This study investigates the influence of testing protocol factors, such as the degree of saturation (DoS), exposure solution composition, sample shape, and the solid-to-exposure solution mass ratio (SLR), on the measured chloride binding capacity of cementitious systems. Samples underwent varying degrees of saturation, including vacuum-saturated, partially saturated, and oven-dried conditions. The exposure solution composition included calcium, potassium, and sodium ions, in addition to pure sodium chloride. Different sample forms (powdered, crushed, and disk-shaped) were explored. Three SLRs of 1:3, 1:6, and 1:10 were also examined for their impact on chloride binding. The results indicated that DoS significantly influences chloride binding, with vacuumsaturated samples exhibiting higher binding capacity than partially saturated and oven dried samples. Additionally, the findings showed that samples in solutions containing additional ions had reduced binding capacities compared to pure chloride solutions. Increasing the sample surface area by crushing or powdering it led to an increase in chloride binding capacity compared to solid, disk-shaped specimens. Lastly, the results demonstrated that increasing the SLR can enhance the binding capacity of the system.