Inspired by the ancient Anji Bridge in Zhaoxian, China, the bridge adopts the structure of a single arch to bear the load, and the distance between the abutments is 14.4 meters. The length of the pedestrian bridge is 26.3 meters and the width is 3.6 meters. The 3D printing concrete system is independently developed by Professor Xu Weiguo's team. It integrates technologies such as digital architectural design, printing path generation, operation control system, printing tool, concrete material, etc. It has high printing efficiency, molding precision and constancy in prolonged work. All of the concrete components are finished in 450 hours, requiring no formwork or reinforcing bar. As a result, its cost is reduced by one third compared to traditional bridges.
The pedestrian bridge consists of three parts: the arch structure, the handrails and the pavements. The structure is printed in 44 hollow-out 3D printed concrete units; the handrails and pavements are also divided into 68 and 64 units. The printing material is composed of polyethylene fiber concrete with various admixtures. After repeated ratio tests and printing experiments, the pressure resistance strength of the new concrete material reaches 65 MPa and the flexural strength reaches 15MPa, which meets the structural requirements.
The design of the pedestrian bridge adopts three-dimensional solid modeling. The bridge handrails are shaped like flowing ribbons on the arch, forming an elegant posture. The pavements patterns are generated from the form of brain corals, and white pebbles are filled in the voids.
The bridge is embedded with real-time monitoring system, including vibrating wire stress sensors and high-precision strain monitoring system, which can collect real-time force and deformation data of the bridge. They will have practical effect on tracking the performance of new concrete materials and the structural mechanical properties of printing components.