## 1 Introduction  
During the service period of concrete pavement, the bearing capacity of the foundation is easily reduced due to the infiltration of surface water. This leads to the formation of a void at the bottom of the pavement, causing the pavement to become prone to cracking. When the concrete pavement reaches its designed service life, various problems will appear successively on the concrete pavement--mainly including corner break, cracks, depressions, pavement pumping, and faulting of the slab ends--which seriously affect road traffic safety. When routine maintenance cannot guarantee the performance of the pavement, it needs to be rehabilitated, and the pavement should be removed or broken up for reuse. The removal cost is relatively high, and it often has an adverse impact on the environment. Recycling after crushing can not only effectively utilize the original concrete pavement, but also effectively solve the problem of reflection cracks in a \"white to black\" rehabilitation project [1, 2]. Among the old concrete-pavement-crushing and reconstruction methods, homogenized micro-crack crushing is a novel concrete-pavement-crushing technology. This method combines the advantages of multiple head breakers, impact compactors, guillotine breakers, and resonant pavement breakers, which makes full use of the bearing capacity of the original pavement and treats the corresponding problems [3, 4, 5, 6, 7, 8]. When old concrete pavement is rehabilitated by homogenized micro-crack crushing technology, special mechanical equipment is used to crush the old concrete pavement. This causes the inside of the cement pavement slab to form oblique micro-cracks evenly distributed in all directions, and the cracked concrete blocks will be interlocked with each other. This not only effectively overcomes the generation of reflection cracks, but also maximizes the bearing capacity of the original concrete pavement. After the old concrete pavement undergoes homogenized micro-crack crushing, the asphalt pavement can be directly overlaid [9]. The homogenized micro-crack rehabilitation of concrete pavement is carried out along the driving direction of the road. Due to problems such as insufficient base bearing capacity and insufficient strength of the concrete pavement in some of the reconstructed sections, if the two front and back impact rupture areas are closely adjacent or partially overlapping during the crushing process, the cracks between the two areas will become connected to each other along the driving direction, as shown in Figure 1. When the asphalt pavement is overlaid, it is easy to produce longitudinal reflection cracks in the driving direction. The local weak base of the concrete pavement can be reinforced by grouting, but the longitudinal crack extension of the cracked areas still needs to be treated so as to better prevent the occurrence of longitudinal reflection cracks in the asphalt pavement. In the homogenized micro-crack crushing of concrete pavement, the crack propagation and the fracture state of the concrete slab are the key points that need to be studied. Low-velocity impact fractures from concrete slab testing will be helpful for understanding the homogenized micro-crack crushing fracture mechanism. In terms of the impact resistance of plain concrete and the different types of concrete-based composites, many low-velocity impact tests have been carried out on concrete slabs. [PERSON], [PERSON], and [PERSON] et al. [10] conducted impact tests and numerical simulations on plain concrete (PC) and fiber-reinforced concrete (FRC), and found that an increase in the fiber volume fraction greatly increased the impact resistance of the concrete specimens. [PERSON], [PERSON], and [PERSON] [11] developed a hybrid steel mesh-and-fiber-reinforced cementitious composite (HSMFRCC) and studied its impact resistance. They found that the impact resistance of HSMFRCC was higher than SMRCC (steel-mesh-reinforced cementitious composites).