The Role of the Type of Mix Water and Ion Concentration on the Fresh State Properties of Mortar

The use of alternative waters rather than freshwater for concrete production is thought to be inevitable in the near future due to water scarcity. One of the alternatives is seawater. While the interest in the topic has increased dramatically and hundreds of papers have been published recently, the reported results in the literature were conflicted. It was attributed to different ion concentrations of seawaters. Moreover, the research on the fresh state properties of seawater cementitious materials has been limited. In that study, the roles of the types of mix water, different ion concentrations, and metakaolin substitution on the fresh state properties of cementitious materials were investigated. The results showed that while the use of seawater slightly decreased flowability, ion concentration did not show a significant effect on it. Freshwater samples showed lower shear stresses than all seawater samples at the same shear strains. Higher ion concentration resulted in increased viscosity. On the other hand, metakaolin substitution was more dominant on the fresh state properties rather than the type of mix water and ion concentration.