Experimental Characterization of Bond Fatigue using Beam-End Tests with Push-In Loading

Realistic characterization of fatigue loading resistance is a paramount for an economical and reliable structural design of reinforced concrete (RC) and prestressed concrete (PC) structures. The need for innovative experimental methods for the characterization of fatigue behavior is driven by the current aims to construct wind turbine towers that must resist up to N=10⁷ loading cycles corresponding to 25 years of service life. Considering the number of possible configurations with regard to structural geometries, cross-sectional layout of reinforcement and loading scenarios, experimental data are required that capture the key mechanisms driving the fatigue damage between the reinforcement and concrete matrix. Experimental investigations of bond behavior under fatigue loading have been reported in the literature in the 90’s of last century. Since then, no systematic investigation of bond fatigue behavior has been published. As a consequence, no assessment rules are available for the bond fatigue, only separate assessment rules for concrete and steel. The present paper will report on the ongoing research of bond fatigue behavior using the beam-end test setup. The test campaign includes the push-in loading with the goal to provide data characterizing the compressive behavior of reinforced cross sections in wind turbine towers.