Influence of cyclic loading on tensile performance of prefabricated UHPC water tank wall joints

The functionality of prefabricated water tanks depends critically on the mechanical performance of their connection joints. Under service and seismic loads, these joints are subjected to cyclic actions, which may aggravate leakage and structural failure compared to monotonic loading. This study examined tensile and leakage behavior of prefabricated ultra-high-performance concrete (UHPC) wall joints through experiments and numerical simulation. Results show that the cracking load under cyclic loading is markedly reduced relative to monotonic loading, although yielding and ultimate loads remain similar. Cyclic loading weakens tank functionality governed by cracking resistance. Specifically, the cracking loads of joints with smooth and roughened interfaces decreased by approximately 46.4% and 36.3%, respectively. Compared with smooth interface, the roughened interface treatment improved the cracking resistance by about 35.4%. Interface roughening enhances mechanical interlock, increasing the initial leakage load by 41.5% and reducing leakage rate during crack propagation by 55.3%. To incorporate cyclic effects in design, a calculation method was proposed for cyclic tensile capacity and characteristic displacement. Prediction errors were generally below 10%, with larger errors observed for cracking displacements under 0.1 mm. The method shows strong agreement with experiments, providing practical guidance for prefabricated storage tank design to ensure serviceability and durability.