# Effect of Calined Marble Powder and Magnetized Water on the Performance of Cement-Based Composites
## 3 Results and Discussion
### Unit Weight, Water Absorption, and Porosity  
Figure 11 presents the unit weight, water absorption, and porosity data of cementitious composites with RMP and CMP substitutions after a curing period of 28 days. Three samples were used for each mixture during these tests, and the average of these values was taken. Figure 12 illustrates the percentage change in unit weight, water absorption, and porosity values of mixtures coded R_/TW, C_/TW, and C_/MW compared to the reference mixtures. Figure 10: Change in compressive strengths of the cementitious mortars for curing. The unit weights of the R_/TW-coded mixtures were measured to be between 1898\(-\)2001 kg/m\({}^{3}\). As the RMP substitution ratio increased, the unit weight values decreased. This phenomenon can be attributed to two reasons. One of these is that the specific gravity of RMP is lower than that of PC [54,55]. The other reason is the reduction in the number of hydrated components and the formation of a more porous structure as the RMP substitution ratio increases. The unit weights of RMP-substituted mixtures were found to decrease by percentages ranging from 1.15% to 5.15% compared to the RQ/TW-coded reference mixture. The obtained results are consistent with findings from the literature [39,56]. The unit weights of the C_/TW-coded mixtures range from 1940 to 2036 kg/m\({}^{3}\). The unit weights of the C5/TW- and C10/TW-coded mixtures showed an increase of 1.75% and 0.90%, respectively, compared to the reference mixture (CQ/TW), while the other mixtures exhibited a decrease ranging from 0.15% to 3.05%. It is observed that increases in unit weight values are achieved with the calcination of RMP. This can be attributed to the contribution of free CaO, formed as a result of the calcination of RMP, to the hydration process and the CMP substitution, creating a denser microstructure compared to RMP. The unit weights of the C_/MW-coded mixtures were measured to range between 2123 and 2063 kg/m\({}^{3}\). The unit weight of the C5/MW-coded mixture showed an increase of 0.71% compared to the reference mixture (CQ/MW), while a decrease ranging from 1.22% to 2.83% was observed with increasing substitution ratios. Additionally, when MW was used as the mixing water, increases in unit weight values ranging from 3.54% to 6.34% were achieved  
Figure 11: The results of the cement mixtures: (**a**) unit weight, (**b**) water absorption, and (**c**) porosity. compared to those produced with TW. This situation can be explained by the fact that the increased activation of MW enhances its reactivity with binding materials, leading to an increase in the number of hydrated elements and resulting in a more compact structure of the cement paste matrix. The findings obtained are also consistent with previous studies in the literature that report that the use of MW increases unit weight. [25; 39; 42; 57]. In Figure 11b, it can be observed that the water absorption rates of the mixtures coded as R_/TW, C_/TW, and C_/MW vary between approximately 9.20% and 9.77%, 9.09% and 9.49%, and 8.64% and 9.11%, respectively. Figure 12b shows the percentage change rates of the water absorption data. As the RMP substitution ratio increases, the water absorption values have also increased. This is attributed to the fact that the increased amount of RMP in the cementitious composites reduces the quantity of materials available for hydration. Consequently, the reduction in the amount of hydrated elements leads to an increase in the volume of voids, which results in a higher water absorption rate [56]. It is observed that there is a decrease in water absorption rates due to the use of CMP substitution and MW, which, as mentioned in previous sections, results in a denser microstructure. The improvement in water absorption rates with MW aligns with previous studies [57; 58]. The lower water absorption observed in MW-containing mixtures can be attributed to a reduction in the pores within the structure of these mixtures.