A comprehensive experimental campaign was carried out to assess the flexural fatigue behaviour of an ultra-high-performance fibre-reinforced concrete. Several concrete mixes were submitted to room temperature, 100 °C, 200 °C, and 300 °C. Two types of reinforcement were explored: steel fibres and a combination of steel and polypropylene fibres. The influence of the addition of fibres and the temperatures in the microstructure were analysed through X-ray CT scans. In addition, the mechanical and fracture properties of the concrete were determined with monotonic tests and a connection between macroscopic and microscopic results was established to explain the fatigue behaviour. The beneficial effect of the fibres was observed essentially at a low cyclic fatigue regime. In heated concretes, the reduction of matrix porosity due to the presence of steel fibres led to significant damage after being exposed to 300 °C by spalling failure. By contrast, the concrete reinforced with polypropylene fibres maintained remarkably similar fatigue behaviour at room temperature and 300 °C.

进行了全面的实验，以评估超高性能纤维增强混凝土的弯曲疲劳行为。将几种混凝土混合物分别置于室温，100°C，200°C和300°C下。探索了两种类型的增强材料：钢纤维以及钢纤维和聚丙烯纤维的组合。通过X射线CT扫描分析了纤维添加和微结构温度的影响。此外，通过单调测试确定了混凝土的力学性能和断裂性能，并建立了宏观和微观结果之间的联系以解释疲劳行为。基本上在低循环疲劳状态下观察到了纤维的有益作用。在加热的混凝土中 由于存在钢纤维而导致的基体孔隙率降低导致剥落破坏暴露于300°C后导致显着损坏。相比之下，用聚丙烯纤维增强的混凝土在室温和300°C下仍具有非常相似的疲劳性能。