ABSTRACT
Although during recent post events surveys it has been observed that several masonry infills have been collapsed or severly damaged due the interaction of the in-plane and out-of-plane seismic actions, the standard prescriptions on the in-plane/out-of-plane interaction of traditional rigidly attached masonry infills are often limited or even missing. Many studies have been accomplished on this topic, also recently, being often focused on infills made of bricks, or “weak” masonry infills with high slenderness. However, the researches and the experimental campaigns related to the out-of-plane behaviour of “strong”/“robust” clay masonry infills, for example made by vertically perforated blocks with thickness larger than 20-25 cm, are very limited. The importance of the topic is also related to the wide adoption of this typology of masonry infill in many countries also due to its thermal and acoustic performance. This paper presents a study on the out-of-plane response of a relatively “strong” infill constructed using tongue and groove clay block masonry units with a thickness of 35 cm. The work is based on the results of an experimental campaign conducted at the University of Pavia and Eucentre on real scale one-storey, one-bay reinforced concrete infilled specimens. A series of cyclic static in-plane and out-of-plane tests has been carried out; the out-of-plane experiments have been executed on an undamaged specimen and on infills previously damaged in-plane, reaching levels of maximum drift equal to 1.00, 1.50 or 2.50%, representing the attainment of different performance levels, in order to evaluate the related out-of-plane resistance reduction. The aim of the study is to define a criterion to compute the out-of-plane resistance of strong masonry infills, through the developmenet of an in-plane/out-of-plane interaction curve, where a reduction coefficient of the out-of-plane resistance of the undamaged panel is function of the in-plane drift of the infilled frame and every data have been obtained from experimental results.
