*3.5. Correlation between Rheological Properties of Pastes and Chosen Properties of Mortars*

A correlation between the rheological properties (plastic viscosity) and WRV was established, as shown in Figure 12 (correlation experimental results after 10 min) and in Figure 13 (correlation experimental results after 60 min). Comparing the individual test results, one can notice a high correlation and interdependence of the plastic viscosity and WRV, especially for materials based on a cement–lime binder (Figures 12b and 13b). The trend showed an increase in WRV with the increase in plastic viscosity. For pastes with a plastic viscosity over 8 N·mm·s, WRV10 and WRV60 were all within the limits. Similar correlations between the rheological properties and water retention value were obtained in the case of cement and lime pastes and mortars in [49,51].

**Figure 12.** Correlation between plastic viscosity and WRV10 (**a**) for all samples, and (**b**) only for samples with cement– lime binder.

**Figure 13.** Correlation between plastic viscosity and WRV60 (**a**) for all samples, and (**b**) only for samples with cement– lime binder.

#### **4. Conclusions**

On the basis of the results presented in this a article, the following conclusions can be derived:


**Author Contributions:** Conceptualization, E.S.; methodology, E.S. and R.D.; validation, E.S. and R.D.; formal analysis, E.S.; investigation, E.S.; resources, E.S.; data curation, E.S.; writing—original draft preparation, E.S.; writing—review and editing, E.S.; visualization, E.S. and R.D.; supervision, E.S.; project administration, E.S.; funding acquisition, E.S. and R.D. Both authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the Kielce University of Technology research program number 02.0.11.00/2.01.01.00.0000 SUBB.BKOB.21.001.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** No new data were created or analyzed in this study. Data sharing is not applicable to this article.

**Conflicts of Interest:** The authors declare no conflict of interest.
