## 4 Results and Discussion
### Discussion
#### 4.2.2 Laboratory Test Samples of Shaping I Hydropower CSGRD  
The relationship between paste margin, mortar margin, and the compressive strength of CSGR (with the target being C\({}_{180}\)20 compressive strength class) over several curing periods (14-day, 28-day, 90-day, and 180-day periods) has been studied. The Pearson correlation coefficients, t-statistics, and \(p\)-values were calculated to determine the strength and significance of these relationships between the paste margin, mortar margin, and compressive strength, as indicated in Table 23. The discussion of the results for the Shaping I CSGRD is provided below:correlation over time also suggests that the influence of paste margin becomes more pronounced as the CSGR cures, making it an important variable in the long-term development of CSGR strength. 1. Insight into Paste Margin vs. Compressive Strength Development  
The data in Table 23 provide insights into the relationship between paste margin and compressive strength at different curing ages: 14 days, 28 days, 90 days, and 180 days. The details are provided as follows:  
* A 14-Day Test Age: The Pearson correlation coefficient is 0.844 with a \(p\)-value of \(1.07\times 10^{-5}\). This strong positive correlation suggests a significant relationship between paste margin and compressive strength at the early curing stage. The very low \(p\)-value indicates that this result is statistically significant, affirming the positive influence of paste margin on the early strength of the CSGR. * A 28-Day Test Age: The correlation decreases slightly to 0.787 with a \(p\)-value of \(1.06\times 10^{-4}\). While the relationship remains strong and statistically significant, the slight decrease in the correlation coefficient suggests that other factors may begin to influence compressive strength as the curing process continues. * A 90-Day Test Age: The correlation coefficient increases slightly to 0.850 with a \(p\)-value of 7.96 \(\times\) 10\({}^{-6}\). This again indicates a strong positive relationship, reaffirming the significant impact of paste margin on compressive strength as the CSGR continues to mature. * A 180-Day Test Age: The correlation returns to 0.787 with a \(p\)-value of 1.06 \(\times\) 10\({}^{-4}\), mirroring the results seen at 28 days. This consistency in correlation strength between the 28-day and 180-day marks suggests a stabilized relationship between paste margin and long-term compressive strength. 2. Remarks on Paste Margin and Compressive Strength Development  
The strong positive correlations across all curing periods in Table 23, coupled with highly significant \(p\)-values, indicate that paste margin is a critical factor in determining compressive strength [14]. The data suggest that increasing paste margin consistently contributes to higher compressive strength, especially in the early stages, with this effect being sustained as the CSGR matures. 1. Mortar Margin vs. Compressive Strength Development  
These negative coefficients (\(-0.544\), \(-0.628\), \(-0.565\), \(-0.628\) for 7-day, 28-day, 90-day, and 180-day curing periods) shown in Table 23 indicate an inverse relationship between mortar margin and compressive strength, where an increase in mortar margin is associated with a decrease in compressive strength. The strength of this negative correlation, however, is moderate and decreases slightly over time, suggesting that while the mortar margin does have an impact on compressive strength, its influence diminishes as the CSGR cures. The t-statistics (2.568, 3.222, 2.748, and 3.222) and the \(p\)-values (1.96 \(\times\) 10\({}^{-2}\), 5.3 \(\times\) 10\({}^{-3}\), 1.46 \(\times\) 10\({}^{-2}\), and 5.3 \(\times\) 10\({}^{-3}\)) for these correlations indicate that while the relationship is statistically significant, it is weaker compared to the paste margin's influence. This suggests that although mortar margin negatively affects compressive strength, its impact is less critical, especially as the CSGR matures [4; 17]. 1.