Experimental tests for seismic assessment of ventilated façades

Abstract

Ventilated facades are currently one of the most used technologies for external envelope of buildings. This kind of external cladding offers many advantages in terms of energy saving, sound insulation, protection of the structures, and has also a considerable architectural value. However, these nonstructural components must have suitable features to ensure their integrity in case of earthquakes. Their damage during a seismic event can have relevant consequences, on the safety of human life, on the operability of strategic buildings and can also have a significant economic impact related to post-earthquake retrofit actions. The aforementioned reasons paved the way to several studies referring to the evaluation of seismic behavior of such components, especially by means of experimental tests, even if up to now no standard procedures for seismic assessment of ventilated facades are available in Europe. This paper focuses on an experimental campaign carried out on a ventilated façade sample, 2.4 m wide and 4 m high. An innovative seismic test facility, located at the Construction Technologies Institute (ITC) of the National Research Council of Italy (CNR) in San Giuliano Milanese (Milan), is used to perform both quasi-static and dynamic tests on the sample.Results of the tests performed by using existing experimental procedures for in-plane crescendo tests, i.e. AAMA 501.4 (2009), are compared with those obtained by applying a new loading protocol proposed by the Authors. The innovative aspect of the latter consists in the introduction of test frequencies closer to those of the buildings usually hosting this kind of façades and then obtaining a more realistic behaviour of the tested specimen. The obtained results will be the basis for the definition of harmonized assessment methods for the seismic evaluation of ventilated façades to be possibly introduced in harmonized European technical specifications.