Yi Liu
i Professor, Dalhousie University, Halifax, Canada, Yi.liu@dal.ca
ABSTRACT
This paper presents the results of an experimental study on masonry columns subjected to concentric and eccentric axial loads until failure. A review of available literature revealed limited experimental studies and data on masonry columns over the past four decades. The current Canadian masonry design standard applies the same provisions for masonry columns as for masonry walls. This study aimed to investigate the behaviour and strength of reinforced masonry columns, providing new physical data using current masonry products and building techniques. Additionally, the results were used to verify the efficacy of design provisions for masonry columns in both the Canadian and American masonry design standards, with a focus on the moment magnifier method. Six masonry columns with slenderness ratios (kh/t) ranging from 6.3 to 15.8 were tested. For each slenderness ratio, two cross-section configurations—constructed with either stretcher blocks or C-shaped blocks—were studied. The experimental results revealed that the failure modes of the specimens depended on their slenderness and loading conditions. At low slenderness and under concentric axial load, failure was characterized by splitting longitudinal cracks and localized crushing, leading to the buckling of longitudinal reinforcement. At higher slenderness and under eccentric axial load, failure was characterized by flexural tensile cracking and compressive crushing, primarily around the midspan of the specimens. As slenderness increased, the capacity of the specimens decreased, with pronounced nonlinearity at the outset of loading. The comparison with design values highlighted the design difference in Canadian and American design provisions. The possible causes for this difference were discussed in the paper.
KEYWORDS: Masonry columns, slenderness effect, eccentric compression loading, moment magnifier method, experimental study.
032-Liu.pdf
