Fatigue performance of post-installed anchorage beams

Abstract

Structures such as industrial factory buildings and highway bridges are subjected to fatigue load during their lives, so it is important to understand the fatigue behaviour of the post-installed anchorage members applied in these structures. The ultimate bearing capacity, stiffness degradation and fatigue life of post-installed anchorage beams were studied by fatigue tests of 6 groups of beams with different embedment depths, loading modes and maximum fatigue loads. A group of cast-in-situ beams was tested as a reference. The similarities and differences between the fatigue and static loading tests were analysed. The stiffness degradation was approximately logarithmic with the number of fatigue load cycle for specimens whose embedment depths are greater than or equal to 20 times the rebar diameter, and the formula of fatigue deformation of the post-installed anchorage beams was determined. According to the double logarithmic distribution relationship between the fatigue strength and fatigue life, the S-N curve of the post-installed anchorage beams was obtained. The results show that the adverse effects of fatigue loading on the beams decrease gradually with an increase in the embedment depth; the damage caused by fatigue loading is concentrated in the first 500 thousand cycles. The failure mode of beams with an embedment depth less than 20 d is brittle failure, while those with an embedment depth greater than or equal to 25 d is ductile failure.