## 5 Results and Discussion
### Service Performance of the Trial Section  
According to the above performance tests of asphalt binders and concretes, it can be determined that the \(DS\) of HSAC7 and \(\epsilon_{\text{B}}\) of ESAC50 failed to meet the specification requirements (JTG/T3364-02-2019) [24]. Although the \(DS\) and \(TSR\) of HSAC13 were ahead of HSAC11, the gap was not apparent. Meanwhile, the \(\epsilon_{\text{B}}\) of HSAC11 was higher, which indicated that it had better low-temperature crack resistance. Furthermore, the increased EP content contributed to the improved high-temperature stability and moisture damage resistance of the concrete. Consequently, HSAC11 and ESAC45 were finally used for the pavement of the trial road. Currently, the pavement has been in operation for one year, and in order to comprehensively compare and understand the quality of the novel bridge deck pavement structure, a comprehensive inspection of its service condition was carried out. Before that, the traffic volume in different directions was enumerated. The results are shown in Figure 10.  
From Figure 10a, it can be seen that the traffic volume of the trial road was highly variable over the months. For the lanes towards Ningbo, the highest monthly traffic volume appeared in March, with 763,000 vehicles; the lowest appeared in October, with 420,000 vehicles. For the lanes towards Chuanshan, the highest and lowest monthly traffic volumes also occurred in March and October, with 750,000 and 409,000 vehicles,  
Figure 10: Traffic volume statistics: (**a**) single-month of traffic volume and (**b**) cumulative traffic volume. respectively. The main reason for this phenomenon is that the traffic control caused by COVID-19 led to a sharp drop in traffic volume during some periods. In general, the traffic volume in the lanes towards Ningbo was higher than that towards Chuanshan. Figure 10b shows the cumulative traffic volume of the two-way lanes. In 2022, the cumulative traffic volume of the lanes towards Ningbo was 7.849 million vehicles, and the cumulative traffic volume of the lanes towards Chuanshan was 6.8% lower compared to the Ningbo direction, which was 7.314 million vehicles. The bridge deck pavement service conditions at K0008+700 to K0008+800 (right) and K0008+800 to K0008+900 (left) were thoroughly tested, and the results are shown in Figure 11.  
SDPCI was used to reflect the damaged condition of the pavement, mainly including cracks, potholes, sinking, and loosening. The results in Figure 11a revealed that the SDPCI of some lanes reached 100, indicating that the surface of these lanes was basically devastation-free. The SDPCI of NB1, NB2, and NB3 lanes reached above 90. In contrast, the SDPCI of the right lanes of CS2 and CS3 were only 77.26 and 84.54, indicating that the pavement in the Chuanshan direction was significantly damaged. The reason for this may be the higher ratio of heavy load vehicles in lanes 2 and 3 compared to lane 1, leading to visible damage to the pavement in a short period, and also demonstrating that the bridge deck pavement constructed using the novel structure of SMAC + EAC had better resistance to defects. Figure 11: Bridge deck pavement evaluation results: (**a**) SDPCI, (**b**) SDRQI, (**c**) SDRDI, and (**d**) SDRWI. The SDRQI quantifies the comfort of a vehicle driving through pavement flatness. As shown in Figure 11b, the gap in SDRQI was not apparent for all lanes except CS3, indicating that the whole driving quality of the bridge deck pavement was satisfactory. Notably, the SDRQI of the left lane of CS3 was significantly lower than that of the other lanes, only 74.28, which was similar to the results in the SDPCI and was mainly affected by the more severe defects existing in the pavement. SDRDI was utilized to evaluate the pavement rutting damage degree. The results in Figure 11c revealed that the SDRDI reached above 90 for all lanes.