# Dynamic Response of Reinforced Recycled Aggregate Concrete Pavement under Impact Loading
###### Abstract  
Airport runway pavements often undergo the direct impact of aircraft landings. For the purposes of designing the structure, it is of great importance to know about the dynamic response of the pavement and its behavior under impact loading. However, the dynamics and failure mechanisms of reinforced recycled aggregate concrete pavements subjected to impact loading are seldom explored in the literature. For this purpose, four reinforced recycled aggregate concrete pavements with different thickness and ratios of reinforcement, and one reinforced normal concrete pavement, were manufactured and tested under impact loading using the drop-weight impact frame system. The impact force characteristics, crack patterns, deformation responses, and strain developments of reinforced concrete pavements subjected to impact loading were evaluated and compared. The above-mentioned study revealed that with an increase in the reinforcement ratio, both the deformation and the steel strain were reduced. Increasing the thickness would reduce the degree of damage and the impact force of reinforced concrete pavement (RCP) but increase the deformation. The results show that under the same compressive strength, the dynamic performance of the reinforced recycled aggregate concrete pavement was worse than that of the reinforced normal concrete pavement because of its lower elastic modulus and weaker interfacial transition zone. The dynamic performance of reinforced recycled aggregate concrete pavement could be improved by increasing the thickness and reinforcement ratio. The use of recycled aggregate concrete (RAC) in RCP is a technically feasible application of the material within the scope of this experimental study. RCP; recycled aggregate concrete; impact loading; impact force; cracking; peak displacement 1  
[PERSON], [PERSON], [PERSON], [PERSON]. engineering accidents. In order to satisfactorily meet these requirements, the pavement must be of sufficiently good quality to ensure not failing under the applied load. Reinforced concrete pavement (RCP) refers to a pavement with embedded steel reinforcing bars in the concrete for crack control. The bars keep the cracks tightly closed, thus allowing longer joint spacing, resulting in an intact and smooth surface that ensures structural integrity and improves the performance of the pavement [4; 5]. Reinforced concrete pavement is widely used in airport runway landing areas due to its good performance and low maintenance needs. The performance of RCP depends on critical stresses and deflections imposed by repeated traffic and environmental loading, and fatigue fracture caused by these stresses is considered to be the limit state in the design of pavement structure. Therefore, in the current design code provisions on pavements, the main task is to determine the thickness of each component of the pavement structure to ensure that it can provide a satisfactory structural life at design fatigue limits. At present, the widely available analysis method of wheel load stress is based on [PERSON]'s elastic thin plate theory [6], and [PERSON] [7] has further proposed the solution of Winkler foundation under different load conditions. With the emergence of finite element software, the mechanical stresses are evaluated by a three-dimensional analysis and thermal stresses by two-dimensional analysis [8; 9; 10; 11]. However, neither the Federal Aeronautics Administration (FAA) nor the Civil Aviation Administration of China (CAAC) considers impact effects due to hard landings of heavy aircraft in the design of airport runway pavements. The design code recommends that the dynamic effect be taken into account by multiplying the dynamic amplification factor. A large amount of abandoned concrete is produced during the reconstruction and extension of airport runways, which has a substantial effect on the environment. Sustainability concerns are at the forefront of our society; unfortunately, the abandoned concrete is a non-renewable resource.