## 3 Results and Discussion
### Durability Performance  
Figure 8 presents the results of the surface abrasion resistance test for six different specimen IDs including the statistical analysis results. The y-axis indicates the amount of weight loss measured after the completion of the abrasion test, with smaller values representing better resistance to abrasion. It was observed that specimens treated with the 30% strontium nitrate solution showed improved surface abrasion resistance performance compared to those treated in deionized water for the same duration. The H1 specimen group exhibited an average weight loss of 1.15 g, while the S1 group recorded an average loss of 1.07 g, indicating that specimens treated for one day with the 30% strontium nitrate solution exhibited approximately 7.0% improved surface abrasion resistance performance. The S3 group (1.05 g) showed about 7.3% better performance compared to the H3 group (1.14 g), and the S7 specimens (1.04 g) recorded about 6.6% higher performance than the H7 group (1.12 g). The \(p\)-value ranged from 0.024 to 0.069 for the test cases, indicating that the \(t\)-test analysis results demonstrated a confidence level for the difference in mean values between the two groups of over 93%. Regardless of the duration of treatment with the strontium nitrate solution, a similar level of improvement in surface abrasion resistance was observed compared to the control specimens (cured in deionized water), suggesting that the performance enhancement is primarily manifested in the early stages of treatment due to the high reactivity of strontium [35]. Figure 9 presents the results of the water sorptivity test for the six different specimen groups. For each group, the average weight change due to water absorption was calculated at each measurement point up to ten days for four specimens and represented graphically. To observe the rate of water absorption at the early stage, the x-axis is represented as day\({}^{0.5}\), and the y-axis shows the weight of water absorbed through the surface of the specimen in grams (g). Water ingress occurs through the capillary pore network of the cement paste specimen, so lower values indicate greater resistance to water absorption. The results show that specimens additionally treated with the 30% Sr(NO\({}_{3}\))\({}_{2}\) solution exhibited superior water absorption resistance in all cases compared to those additionally cured in deionized water for the same period. The group treated with strontium cations for 1 day (S1) showed about 9.0% improved performance compared to H1, and for the 3-day additional curing condition, S3 exhibited about 31.3% improved performance compared to H3. Furthermore, for the group treated for an additional 7 days, S7 showed about 38.0% higher water absorption resistance than H7. In other words, while strength-related characteristics were significantly manifested at the early stages of the treatment, the resistance to water  
Figure 8: Results of surface abrasion resistance test. absorption increased as the duration of treatment with strontium cations lengthened. This is presumed to be due to a reduction in the distribution of capillary pores that influence water absorption as the strontium treatment period increases. Notably, the rate of water absorption in the early stages for the strontium-treated specimens (S1, S3, and S7) was significantly slower compared to the control group (H1, H3, and H7). Figure 10 shows the results of the porosity measurements for the six specimen groups with the \(t\)-test analysis results. The average porosities for the H1 and S1 groups were 7.05% and 6.09%, respectively, indicating that a 13.7% reduction in porosity occurred due to an additional day of curing in 30% strontium nitrate solution. The S3 group, with a porosity of 5.50%, had approximately 21.0% less porosity compared to the 6.97% in the H3 group. Similarly, the porosity of the S7 group, treated with the strontium solution for 7 days, was 5.16%, which is about 25.9% lower than the 6.96% of the H7 group.