Assessment of the influence of Nano-Silica on the behavior of mortar using factorial design of experiments

The influence of water/cement ratio and addition of Nano-Silica as partial replacement of cement on the compressive strength and water absorption of mortar mixes is a topic of current research. For this purpose, 32 factorial design is selected with water/cement ratio and Nano-Silica (%) as factors. The levels of water/cement ratio are kept at 0.40, 0.45 and 0.50. The levels of other factor Nano-Silica (%) is kept at 0%, 1.5%, and 3%. Compressive strength at 3, 7, and 28 days and water absorption at 28 days are selected as responses. The Analysis of Variance (ANOVA) of test results for aforementioned responses considering the factors depict that the selected factors are significantly affecting the test results. However, the analysis indicates that interactions of factors are not statistically significant. In addition to the above, the study illustrates that consistency and setting time of cement paste is considerably affected by the incorporation of Nano-Silica.