3D printed construction and mechanical properties analysis of unreinforced concrete arch structure

This paper presents a feasibility study on 3D printed lightweight concrete arch structures, examining three key aspects: design, construction, and load-bearing performance. Based on the characteristics of arch structures and 3D printing technology, a segment-assembly method was proposed to realize the accurate and fast assembly of arch structures. On this basis, five 3D printed lightweight arch structure specimens were constructed. The influence of three conditions, namely two-point concentrated load, three-point concentrated load, and uniformly distributed load, as well as the printing paths of “π”, “W”, and “M” cross-sections, was studied through experiments on the bearing performance of arch structures. Additionally, the mechanical behavior of 3D printed concrete arch structures with rise-span ratios of 1/4, 1/6, and 1/8 was analyzed using finite element calculations. The results show that the cooperative deformation ability of each segment and bearing capacity of the specimens under uniformly distributed load are the best, and the compressive advantage of 3D printed concrete materials can be fully utilized. The local collapse of the arch structure is easy to be caused by concentrated load, and the ultimate bearing capacity of arch specimens under two-point and three-point concentrated loads decreases by 30.2% and 14.2% respectively compared to that under uniformly distributed load. The specimen with “M” cross section printing path has the best force transfer mechanism, and the peak load per unit mass increases by 23.2% and 28.4%, respectively, compared with the specimens with “π” and “W” printing paths. Within the recommended range of rise-span ratios specified, the bearing capacity of 3D printed concrete arch structures gradually decreases as the rise-span ratio decreases. All five specimens investigated in this experiment demonstrate good load-bearing performance.