## 1 Introduction  
Buildings may be subjected to a variety of accidental loads throughout their design service life, such as collisions, impacts, and explosions. Examples include the impact caused by a precast component falling while hoisting a lower component, or the impact caused by stones rolling onto buildings in mountainous areas. These loads, with their short durations and high peak values, pose a threat to the structural safety of a building. Impact loads should be taken into account in structural designs using reinforced concrete beams in particular situations to prevent catastrophic structural progressive collapse, and the impact resistance of existing structural parts should be evaluated. Therefore, it is important to perform research on the impact resistance of building materials. Precast concrete (PC)is gaining popularity in infrastructure and building projects due to its widespread use in residential and commercial structures, tunnels, bridges, metro stations, and roads. Its advantages include faster construction, enhanced quality control, reduced construction waste, and improved durability and stability, which reduces the reliance on labor and materials used in traditional concrete construction. Additionally, investigations on precast reinforced concrete composite beams strengthened by adhesive steel are few in comparison to the studies on cast\(-\)in\(-\)place reinforced concrete beams. Research conducted on the seismic performance, impact resistance, damage modes, and associated damage mechanisms of precast assembled concrete stacked beams reinforced with viscous steel is therefore practically important for actual engineering designs and safety assessments. Many scholars have conducted experimental investigations on the impact resistance of reinforced concrete (RC) beams cast in place and precast reinforced concrete (PC) beams. [PERSON] et al. [1] and [PERSON] et al. [2; 3] conducted experimental studies to investigate the impact resistance of reinforced concrete (RC) beams and ultra\(-\)high\(-\)performance concrete (UHPC is further researched and developed on the basis of traditional concrete with greater strength, better durability, and a superior engineering performance) beams with varying reinforcement ratios. It was found that increasing the reinforcement ratio could make a beam more rigid overall, reduce damage and displacement, and make components more impact\(-\)resistant. [PERSON] et al. [4] employed a 3D mesoscopic simulation approach, accounting for concrete heterogeneities, to investigate the effect of the hoop ratio on the impact resistance of the member. Their findings indicate that the hoop ratio has a negligible impact on the mid\(-\)span deflection of the beam under the impact load. [PERSON] et al. [5] performed a finite\(-\)element study on reinforced concrete beams with different hoop ratios and showed that the configuration of hoops was able to limit the development of diagonal cracks in the beam web. [PERSON] et al. [6] performed drop weight impact tests on 15 RC beams and investigated the impact resistance of these beams by studying the effect of the cross\(-\)section size. The authors discovered that when the cross\(-\)section size of a beam was increased, the stiffness was affected, which in turn led to an increase in the impact force. However, this increase in the impact force leads to a decrease in the peak and residual values of a mid\(-\)span displacement. [PERSON] et al. [7] conducted the drop weight impact tests of UHPC and normal RC beams, and observed that UHPC beams had better impact resistance. [PERSON] et al. [8] proposed a strengthening design method, in which an additional ultra\(-\)high\(-\)performance concrete (UHPC) layer was used to improve the impact resistance of the RC beam and found that the UHPC layer could absorb part of the impact energy in the early stage of the impact process to improve the impact resistance of the test beam. Moreover, the thicker the UHPC layer, the better the impact resistance. [PERSON] et al. [2], [PERSON] et al.