Flexural Behavior of Confined Masonry Walls Subjected to In-Plane Lateral Loads

Abstract

Results of a study on the flexural behavior of confined masonry walls are presented. Six walls were tested in a laboratory under reverse cyclic loads. The variables studied were the wall aspect ratio and wall axial compressive stress. The behavior of walls was characterized by yielding of the longitudinal steel reinforcement of vertical confining elements followed by vertical and diagonal cracks on the masonry panel. The failure of walls was associated with crushing concrete of vertical confining elements. Flexural strength increased as the wall aspect ratio decreased or the wall axial compressive stress increased. The flexural strength of walls was validated using flexural theory. A displacement ductility capacity of 6 and a drift ratio capacity of 1% were proposed for the walls. A hysteretic model based on four parameters was calibrated. This model represented well the flexural behavior of the studied walls.

Lateral in-plane seismic response of confined masonry walls: From numerical to backbone models

“…Then, as the drift increases, horizontal flexural cracks propagate into the masonry panel and new flexural cracks appear along the height of the tie-columns. This is a much more ductile mechanism, as is evident from the experimental results by Varela-Rivera (2019)[3] and da Porto et al(2011)…”

“…So, a backbone model ending with a horizontal plastic branch and allowing for a larger ultimate drift (e.g. 1% as proposed by Varela-Rivera (2019) [3]), may be more suitable and will be adopted in this work for the flexural-dominated failure mechanism.…”

“…CM wall failing by flexure presents a different behaviour, see Varela-Rivera et al (2019)[3]. In this case, damage starts with horizontal flexural cracks at the bottom part of tie-columns.…”

“…Indeed, the assumed diagonal shear failure of CM walls has biased the design of CM walls, so that the prescriptions given in design codes always induce a shear-dominated behaviour. Varela-Rivera et al (2019) [3] have studied the flexural behaviour of CM walls and they advocate reducing the amount of steel reinforcement in tie-columns to induce flexural behaviour rather than shear behaviour, since the flexural failure is more ductile.…”

Structural Performance of Energy Efficient Geopolymer Concrete Confined Masonry: An Approach towards Decarbonization

“…Therefore, poor design and detailing can result in buildings that are susceptible to earthquake damage [2,3]. Unreinforced masonry structures perform well when subjected to gravity load, due to the reasonable compressive strength of masonry units, but on the other hand, it becomes a challenge for the engineers to enhance the tension and shear capacity of masonry structures to achieve improved sustainability during seismic excitations [4,5]. Unreinforced masonry still finds broad use in existing structures across most seismic regions.…”