Role of water film thickness in rheology of CSF mortar

In a recent study, the authors have demonstrated that the combined effects of water content, packing density and solid surface area on the rheology of cement–sand mortar may be evaluated in terms of the water film thickness (WFT). The present study aims to extend the concept of WFT to mortar containing condensed silica fume (CSF). For the study, mortar samples with various CSF and water contents were made for packing density, flowability and rheology measurements. It was found that although the effects of adding CSF are fairly complicated, the WFT is still the single most important parameter governing the rheology of CSF mortar. However, the rheological properties are dependent also on the CSF content. Correlations of the rheological properties to both the WFT and CSF content yielded R2 values of at least 0.896.