# Effect of Calined Marble Powder and Magnetized Water on the Performance of Cement-Based Composites
## 3 Results and Discussion
### Compressive Strength (\(f_{\text{cs}}\))  
Figure 9 presents the \(f_{\text{cs}}\) data of cementitious composites with RMP and CMP replacements after curing periods of 3, 7, and 28 days. The \(f_{\text{cs}}\) tests were conducted on six samples for each mixture, and the average values were calculated. Figure 10 illustrates the percentage changes in \(f_{\text{cs}}\) values of RMP- and CMP-replaced mortars coded as R_/TW, C_/TW, and C_/MW compared to the reference mortars at 3, 7, and 28 days. As observed in Figure 9, there is a trend in the \(f_{\text{cs}}\) values that is similar to that of the \(f_{\text{fs}}\) values, with RMP replacement leading to lower \(f_{\text{cs}}\) values, while higher \(f_{\text{cs}}\) values are achieved with CMP replacement. In the case of CMP-replaced mortars, using MW as the mixing water results in higher rates of increase in \(f_{\text{cs}}\) values. Additionally, as the RMP replacement ratio increases, decreases in the 3-, 7-, and 28-day \(f_{\text{cs}}\) values are noted for the mortars coded as R_/TW. Upon examining the percentage change rates presented in Figure 10, it is evident that the \(f_{\text{cs}}\) values of RMP-replaced mortars at 3, 7, and 28 days show decreases of 6.5% to 32.8%, 7.8% to 28.4%, and 4.8% to 28.7%, respectively, compared to the reference mortar coded as RQ/TW. Similar decreases in \(f_{\text{cs}}\) values with increasing RMP replacement ratios have also been reported in the study by [PERSON] et al. [48]. [PERSON] et al. [7] used RMP as a cement replacement at ratios of 5%, 7.5%, 10%, and 15% in concrete mixtures and observed declines in \(f_{\text{cs}}\) values with increasing RMP replacement ratios. They attributed this reduction to the decrease in the cementing materials (C3S and C2S) responsible for concrete strength. The \(f_{\text{cs}}\) values of mortars coded as C5/TW show increases of 20.4%, 8.5%, and 5.4% at 3, 7, and 28 days, respectively, compared to the reference mortar coded as C0/TW. Similarly, the \(f_{\text{cs}}\) values of C5/MW mortars show increases of 25.6%, 7.4%, and 5.0% compared to the reference mortar coded as C0/MW. These results indicate that the highest \(f_{\text{cs}}\) values in CMP-replaced mortars are typically achieved with a 5% replacement ratio. In a similar study, [PERSON] [49] reported increases in the \(f_{\text{cs}}\) values of concrete mixtures with a 5% MP replacement. He attributed these improvements to the filling effect of limestone powder, which fills the pores and provides suitable nuclei for hydration, thus accelerating the hydration process. However, as the MP replacement ratio increased, a decline in compressive strength was observed. This reduction was attributed to the dilution When comparing the mortars coded as C\({}_{-}\)/TW with those coded as R\({}_{-}\)/TW, the decrease in \(f_{\rm cs}\) values for CMP-replaced mortars is less pronounced than that for RMP-replaced mortars. Notably, increases in fcs values were also observed following the calcination of RMP. The 28-day \(f_{\rm cs}\) values of the mortars coded as C5/TW, C10/TW, C15/TW, C20/TW, and C25/TW showed increases of 10.78%, 11.49%, 13.53%, 14.94%, and 15.81%, respectively, when compared to the mortars coded as R5/TW, R10/TW, R15/TW, R20/TW, and R25/TW. This situation is attributed to the formation of free CaO as a result of the calcination of RMP, which, as mentioned in the section presenting the \(f_{\rm fs}\) results, contributes to the hydration process. The formation of hydration products leads to a denser microstructure, ultimately improving the mechanical properties [16]. Similar results have also been observed in cement mixtures with calcined material additions [50; 51; 52]. Similarly, when comparing the \(f_{\rm cs}\) values of C\({}_{-}\)/TW-coded mixtures with those of C\({}_{-}\)/MW-coded mixtures, it has been observed that using MW as the mixing water results in increases in the \(f_{\rm cs}\) values by varying percentages of 13.4% to 19.3%, 9.3% to 12.6%, and 7.8% to 10.9% for 3, 7, and 28 days, respectively.