Influence of concrete compressive strength on fatigue behaviour under cyclic compressive loading

The development in the building industry is moving towards slimmer, higher and more resource efficient constructions. In reinforced concrete construction, high performance (HPC) and ultra-high performance concretes (UHPC) were developed for these purposes. Components with high slenderness in applications with frequently changing load situations, especially in the area of wide-span bridges and wind turbines, must not only withstand high static loads, but also high fatigue loads. But the fatigue behaviour of HPC and UHPC is still under research. Therefore, tests were carried out on cylinders to determine the fatigue strength. The strain development is considered as a good damage indicator and provides reliable information about the current damage development. It is known that the strain development depends on different factors such as the moisture content. After investigations on the influence of frequency, the maximum stress level and the maximum aggregate size, the influence of the concrete's compressive strength will be presented in this paper. An HPC and a UHPC, were used to determine the extent to which the different concrete strengths have an influence on the number of cycles to failure, the temperature and strain development. For this study, different maximum and minimum stress levels on HPC as well as UHPC will be investigated.