## 2 Experimental Program
### Activation Process  
As high temperatures cause softening of the structural adhesive, degradation of the adhesive will directly impact the ultimate reinforcement effect. Therefore, conducting Fe-SMA activation tests at high temperatures and monitoring the temperature during the activation process is of significant importance. After preparation of the test specimens, high-temperature activation tests are carried out after three days of pressure curing. Before heat activation, four temperature measuring points are arranged at both ends of the concrete anchor bolt hole and on the upper side. Three temperature measurement points are arranged outside and in the center of the activation area of the Fe-SMA plate to monitor the temperature of the specimens during the activation process. The high-temperature activation experimental device is shown in Figure 7. The activation area of the Fe-SMA plate is heated using a hot air gun, and the temperature changes displayed at the temperature measurement points in the activation area are monitored in real time. The activation temperature of the Fe-SMA plate reaches 250 \({}^{\circ}\)C and is maintained for 1 min. The entire heat activation process lasts for ten minutes. For the specimen Con-1, no significant phenomenon is observed during the heat activation process when the activation temperature is below 120 \({}^{\circ}\)C. When the activation temperature exceeds 120 \({}^{\circ}\)C, slight shrinkage can be observed in the Fe-SMA plate. At the same time, an increase in strain can be observed in both the Fe-SMA plate and the concrete. As the activation temperature further increases, the strain growth rate accelerates. During the cooling process, the strain growth rate of Fe-SMA further accelerates. As the temperature decreases, the internal prestress of the reinforced concrete specimens further increases, and the overall anchorage is good. The specimen Con-1 is not damaged during the reinforcement process. The reinforcement process is shown in Figure 8.  
Figure 6: Arrangement of measuring points: (**a**) strain gauges of Fe-SMA; (**b**) strain gauges of concrete; (**c**) strain gauges on the surface of concrete specimen; (**d**) strain gauges on the side of concrete specimen; (**e**) strain gauges of Fe-SMA plate in specimen Con-1; (**f**) strain gauges of Fe-SMA plate in specimen Con-2. For the specimen Con-2 connected by anchor bolts, the activation process is shown in Figure 9. During the heat activation process, no significant phenomenon is observed in the Fe-SMA plate when the activation temperature is below 120 \({}^{\circ}\)C. When the activation temperature exceeds 120 \({}^{\circ}\)C, a significant increase in local strain is detected at the Fe-SMA plate and concrete anchor bolt holes, and the strain growth rate accelerates with a further increase in activation temperature. During the cooling process, the strain growth rate of the Fe-SMA further accelerates. As the temperature decreases, the stress of the reinforced concrete specimen near the anchor bolt hole further increases, and the local compressive stress of the concrete near the anchor bolt hole is much greater than that of the other two specimens. Throughout the entire heat activation process, the anchor bolts are securely anchored and there are no adverse changes observed. Figure 8: Activation process of specimen Con-1: (**a**) overall view; (**b**) side view. Figure 7: Activation device: (**a**) activation method; (**b**) activated surface. For specimen Con-3 connected by the structural adhesive, the activation process is shown in Figure 10. During the heat activation process, no obvious phenomenon is observed when the activation temperature is below 120 \({}^{\circ}\)C. When the activation temperature exceeds 120 \({}^{\circ}\)C, it can be observed that the Fe-SMA plate shrinks, and as the activation temperature further increases, the strain growth rate accelerates.