In this paper experimental investigations of the bond behavior between high-strength concrete and steel rein-
forcement under static and cyclic loading are presented. The tests were mainly conducted with beam-end
specimens and supplementary with classical pull-out samples. The experimental program included 67 quasi-
static and 56 cyclic tests on two high-strength concretes and one normal strength concrete, whereby a very
short bond length of twice the bar diameter was used. The results of the static tests showed a linear relationship
between the bond strength and the concrete compressive strength for a pull-out failure. In the static beam-end
tests, splitting cracks were generally observed resulting in a lower bond strength than that from the pull-out tests.
Based on the static bond strengths, samples were exposed to cyclic loading with up to 20 million load cycles. In
these tests, both the influence of the upper stress level and the loading frequency was investigated. In general, the
number of load cycles until fatigue failure varied greatly despite almost the same stress range. The causes of the
excessive scattering are discussed in particular in relation to existing S-N curves. With regard to the increase in
slip under cyclic load, both the specimens with and without failure showed a clear dependence on the concrete
compressive strength. Based on these results, a modified approach for the displacement factor is presented.
Finally, the results are critically reviewed and recommendations for further investigations are given.