• Speck, Kerstin
• Koschemann, Marc
• Curbach, Manfred
• Kühn, Tino

Abstract

Due to the progressive research and advancement, high performance concrete becomes more important as construction material for structural engineering. This means that beside the questions after the ultimate limit state and serviceability under static loading, also the behaviour under high cyclic loading requires a secure prediction. Exemplary are wind exposed structures like wind power plants, which have to withstand up to N = 109 load reversals during service life. The presented study sets the focus on the bond behaviour between concrete and steel reinforcement under very high cyclic fatigue (N > 2·106) and the influence of compressive strength of concrete, loading frequency and loading velocity as well. Hence, an experimental program with about 110 static and cyclic tests with normal up to ultrahigh performance concrete and two different specimen types is in progress. To operate the experimental studies a test setup has been developed, which allows the simultaneous testing of two specimens. Depending on the static bond strength, the tensile cyclic loading will be applied with a defined lower stress level and different upper stress levels with a frequency from 5 up to 20 Hz. It is intended to detect and show the progress of deterioration by using the recorded bond stressslip-relation and the ratio of slip to number of load cycles. The test setup and the concept of the experimental studies will be shown as well as the results of the first test series.

Topics

• impedance spectroscopy
• strength
• steel
• fatigue