Behaviour of steel frames infilled with environmentally and structurally favourable masonry units

Abstract

The interaction of a steel frame and its masonry infill under horizontal loads has both beneficial and detrimental aspects, both complex to encompass in design guidelines due to a large number of variables. There are various approaches to this problem, among which a popular research theme in steel is the omission of infill influence on the steel frame, to prevent detrimental effects. With this in mind, our previous research was devoted to the development of environmentally and structurally favourable masonry units, which would magnify beneficial aspects of steel-frame interaction and alleviate negative aspects. This research was a continuation of such efforts in the form of cyclic testing of steel frames infilled with newly developed masonry units. An experimental investigation on four various types of steel frame and infill and a bare frame was executed, i.e. various configurations of frame-infill systems were tested under cyclic load. The structural behaviour properties of these configurations are studied and evaluated based on obtained hysteresis loops and their envelopes – ductility, initial stiffness, and ultimate load. In comparison with previous research results on frame infill configurations with different kinds of infill, promising results obtained in the development of masonry units were verified. Frame infilled with new units has high ductility and robustness, combined with lower initial stiffness. This ensured the preservation of the frame from stronger detrimental effects, with enchantments of positive aspects of the frame-infill interaction.