Inelastic seismic behavior of post-installed anchors for nuclear safety related structures: Generation of experimental database

• Experiments for evaluating seismic behavior of anchors were performed.
• Two undercut anchor products in use in nuclear facilities were considered.
• Monotonic tension, shear and cycling tension tests at different crack widths.
• Crack cycling tests at constant, in-phase and out-of phase tension loads.
• Characteristics for the two anchors as a function of crack width were identified.

Post installed (PI) anchors are often employed for connections between concrete structure and components or systems in nuclear power plants (NPP) and related facilities. Standardized practices for nuclear related structures demand stringent criteria, which an anchor has to satisfy in order to qualify for use in NPP related structures. In NPP and related facilities, the structure–component interaction in the event of an earthquake depends on the inelastic behavior of the concrete structure, the component system and also the anchorage system that connects them.For analysis, anchorages are usually assumed to be rigid. Under seismic actions, however, it is known that anchors may undergo significant plastic displacement and strength degradation. Analysis of structure–component interaction under seismic loads calls for numerical models simulating inelastic behavior of anchorage systems. A testing program covering different seismic loading scenarios in a reasonably conservative manner is required to establish a basis for generating numerical models of anchorage systems. Currently there is a general lack of modeling techniques to consider the inelastic behavior of anchorages in structure–component interaction under seismic loads.In this work, in view of establishing a basis for development of numerical models simulating the inelastic behavior of anchors, seismic tests on two different undercut anchors qualified for their use in NPP related structures were carried out. The test program was primarily based on the DIBt-KKW-Leitfaden (2010) guidelines for testing of fastening for use in NPP. The testing program consisted of monotonic and cyclic tests in non-cracked and cracked concrete specimens with different crack widths. In addition, crack cycling tests at design tension load, and simultaneous tension and crack cycling tests (in-phase and out-of-phase) were also conducted. The present paper deals with the details of the tests performed and the results obtained. The development of numerical models simulating anchor inelastic behavior based on the results given in the present paper will be presented in another paper.