The safe use of Strain-hardening Cement-based Composites (SHCC) for structural and nonstructural
applications often requires a solid knowledge of the mechanical performance of this
material under cyclic loading. In the previous investigations the behaviour of SHCC subjected
to a deformation-controlled tension regime was studied.
The article at hand presents the experimental results obtained from the fatigue tests performed
with a fixed force level for the upper (in tension) and lower reversal points of the loading cycles.
The varying parameters under investigation were the upper and the lower stress levels.
Moreover, two different definitions for the upper force level were applied. In the first approach
the upper force level was fixed as a value related to the average first crack stress of the particular
series (for example 80 % of that average value). In the second approach the upper reversal point
was individually defined in relation to the first crack stress of the specimen under investigation
in the course of the testing process (i.e., for example 80 % of the first stress measured on this
particular specimen). The lower reversal point varied between tension and compression.
The experiments were performed on uniaxially loaded dumbbell-shaped prisms. It was
observed, that, as expected, the number of load cycles to failure decreased with increasing upper
stress level. Additionally, the strain capacity increased with decrease in the upper stress level
from 80 % to 60 % of the first crack stress. A further reduction of the upper stress level caused
no change in the failure strain level. After mechanical testing, the crack patterns on surfaces of
the specimens were analysed and optical investigations of the SHCC fracture surfaces were
performed to provide insights into the failure mechanisms specific for the fatigue behaviour of
SHCC. Finally, the experimental results were discussed in particular with respect to the
identification and description of the decisive mechanisms determining the material performance
under force-controlled loading.