Tailoring Experimental Strategy and Setup: the Long Story of the Seismic Behaviour of Precast Structures

Devising the most appropriate testing strategy and conceiving a mock-up “as simple as possible, but not simpler” is the challenge which has to be taken whenever a research programme does involve experiments. Optimizing the experimental programme reduces the risk of either wasting time and resources or missing some of the fundamental ingredients of the structural behaviour because of oversimplification or inclusion of too many elements at the same time. The European Laboratory for Structural Assessment and ASSOBETON have been involved in many research programmes aimed at studying the seismic behaviour of precast concrete structures, with different goals and different levels of complexity. A first programme was aimed at obtaining information about the cyclic behaviour of precast concrete columns. This apparently simple task resulted into an innovative experimental setup because of the need to properly allow for the elongation of the rebars in the region above the pocket foundation. A second programme was aimed at comparing the behaviour of precast and cast in situ frames, and involved the cyclic and pseudodynamic testing of two different mock-ups. Another programme focused on the global behaviour of single-storey precast industrial buildings. In this case the mock-up reproduced in nearly full scale a portion of the building, including foundations, columns, main and secondary beams as well as claddings. The decisions about how to deal with such a flexible structure in a pseudodynamic context had to be made with much care. The paper provides a description of the experimental programmes, highlighting the strategies which were adopted in each case to meet the research requirements. Finally, a description of the recently started EU-funded research programme SAFECAST is provided. This programme focuses on the seismic behaviour of connections in precast structures and will involve pseudodynamic testing of a multi-storey precast structure, with and without cast in situ core.