## 3 Experimental Results and Analysis
### Granite Damage Development and Three-Dimensional Evolution of Cracks
Conversely, under a loading rate of 0.02 mm/s, these signals first emerge at the upper end of the specimen before gradually propagating toward the inner part, with their number and energy intensifying while the density strengthens. Concurrently, at the same stress level of the specimen, both the quantity and energy of the acoustic emission signals increase under a loading rate of 0.02 mm/s, resulting in the most severe damage to the specimen. The ultimate damage pattern observed in the compression test of the specimen further corroborates the accuracy of the acoustic emission development process. Regarding the distribution of damage and energy percentages under each loading rate, the trends in the acoustic emission energy and damage percentages mirror those observed at 30 \({}^{\circ}\)C and do not necessitate repetition. Figure 4: Acoustic emission evolution diagram of different loading rates at 30 \({}^{\circ}\)C.  
Figure 5: Acoustic emission evolution diagram for different loading rates at 40 \({}^{\circ}\)C.  
Figure 6: Acoustic emission evolution diagram for different loading rates at 60 \({}^{\circ}\)C.  
Figure 7: Acoustic emission evolution diagram for different loading rates at 80 \({}^{\circ}\)C.  
As shown in Figure 6, at 60 \({}^{\circ}\)C, under loading rates of 0.005 mm/s and 0.01 mm/s, discrete acoustic emission signals initially manifested in the lower left and lower right corners of the specimen. These signals then propagate inward, with a continuous increase in both number and energy, indicating the formation of through cracks and impending specimen damage. Conversely, under the 0.02 mm/s loading rate, acoustic emission signals first emerge at the ends of the specimen and progress toward the middle, ultimately leading to the formation of cracks in the upper and lower parts of the specimen, resulting in specimen damage. The acoustic emission monitoring process closely mirrors the test results. The distributions of damage and energy shares at loading rates of 0.005 mm/s and 0.01 mm/s, respectively, primarily occur in the middle and late stages of the fracturing process. However, at a loading rate of 0.02 mm/s, they predominantly occur in the early and late stages of rock fracturing. This pattern differs from that observed at 30 \({}^{\circ}\)C and 40 \({}^{\circ}\)C, where the damage and energy shares at a loading rate of 0.02 mm/s are mainly concentrated in the early and late stages of rock fracturing. As observed in Figure 7, at 80 \({}^{\circ}\)C, under loading rates of 0.005 mm/s and 0.01 mm/s, the acoustic emission signal points in the early stage of specimen compression initially exhibit a discrete distribution at the lower end and then progress toward the middle and upper parts, respectively. At the 0.02 mm/s loading rate, acoustic emission signals simultaneously appear at the top and bottom ends of the specimen and then propagate toward the middle, ultimately resulting in through-crack formation. These findings closely align with the test results, demonstrating the effectiveness of acoustic emission monitoring. The distributions of damage and energy shares under loading rates of 0.005 mm/s and 0.01 mm/s, respectively, are primarily concentrated in the middle and late stages of rock fracturing. Conversely, under the 0.02 mm/s loading rate, they mainly occur in the early and late stages of uniaxial compression, mirroring the observations at 60 \({}^{\circ}\)C.  
According to Figures 4-7, according to the distributions of the damage and energy ratio under each loading rate, the damage is positively correlated with the energy ratio and the distribution of the acoustic emission signal. Under each temperature condition, the acoustic emission evolution laws at the different loading rates exhibit certain differences.