Figure 5: Crack width cycle as function of the time for the crack-bridging classes with index T

In the tests for the crack-bridging classes with the index T+L the function plotted in figure 5 was superposed by two periods with higher frequency (5 Hz). These additional dynamic movements were conducted during the periods without crack width change, the plateaus in the upper function. The total duration of the crack-bridging test was constant. The corresponding crack width function for the classes with index T+L is illustrated in figure 6.