# Dynamic Response of Reinforced Recycled Aggregate Concrete Pavement under Impact Loading
###### Abstract
The authors also reported that the acceleration, velocity, and displacement decreased due to an increase in the support stiffness. [PERSON] et al. [29] studied two-way reinforced concrete slabs over different kinds of yielding supports and concluded that reducing the support rigidity could decrease the displacement and stress of the whole structure. [PERSON] et al. [30] found that the energy-absorbing capacity was decreased by an increase of span size in both fixed and free supported RC slabs, and that the maximum midspan displacement values increased only in free supported RC slabs; however the span size has no considerable effect in fixed supported RC slabs. Furthermore, some studies were made to improve the impact behavior of RC slabs by blending in other materials, such as steel fibers, carbon fabric, polypropylene fiber, etc. An experimental program by [PERSON] et al. [31] revealed that the increased addition of the steel fibers was effective in increasing slab capacity, reducing crack widths and spacings, and mitigating local damage under impact. The research by [PERSON] et al. [32] investigated blending steel fibers; carbon fabric showed substantial advantages in the resistance to the impact load and to the penetration of the impactor but had only a minor influence on concrete strain. [PERSON] et al. [33] studied the impact resistance of RC slabs blending with polypropylene fiber; the result showed that the proper quantity of polypropylene fiber could significantly improve the impact resistance of RC slabs, and that a suitable content of polypropylene fiber was 0.90%. [PERSON] et al. [34] studied the impact resistance of concrete slabs blending with four substances (polyolefin, polyvinyl, alcohol, and steel); the result showed that hooked-end steel fiber concrete slabs had the best cracking and energy absorption characteristics compared to other slabs. However, there are a limited number of studies that comprehensively explore the impact dynamics and failure mechanisms of reinforced recycled aggregate concrete pavement. [PERSON] [35] studied the damage and failure model of rigid concrete pavement under drop weight impact, and obtained the extent of damage, failure mode, deformation, and acceleration. The test results show that the concrete pavement without steel reinforcement was fragmented into three segments and showed brittle failure mode. [PERSON] et al. [36] analyzed the dynamic deflection and velocity response of airport concrete pavement under impact loading and drew the conclusion that the velocity response amplitude decreased with the increase of slab thickness, and that the deflection at the center of the slab decreased with the decrease of pavement slab size. Most of the studies conducted under impact loading were focused on natural aggregate concrete (NAC) structural elements. Recently, a few studies have been performed on the dynamic response of RAC structural elements under drop weight impact loading [37; 38; 39; 40]. [PERSON] et al. [38] studied the behavior of RAC slabs under impact loading with different replacement ratios of RCA and found that the stiffness of RAC slabs decreased with an increasing replacement ratio of RCA, which led to decreases in the punching shear strength at first crack stage and in the ultimate punching shear strength. In order to design the airport pavement scientifically and to ensure its service life and safe operation, it is necessary to conduct experimental research on the performance of reinforced recycled aggregate concrete pavement under likely impacts. In fact, the excessive pavement damage due to the impact load of hard landings is extremely difficult to measure. Therefore, in order to better understand the behavior of reinforced recycled aggregate concrete pavement subjected to impact loading, an experimental program has been designed and conducted in this paper.